Deldicque L,De Bock K, Maris M, Ramaekers M,Nielens H, Francaux M, Hespel P (2009) Increased p70s6k phosphorylation during intake of a protein–carbohydrate drink following resistance exercise in the fasted state. European Journal of Applied Physiology
http://www.springerlink.com/content/w8712615714k8150/
Abstract
The present study aimed at comparing the responses of myogenic regulatory factors and signaling pathways involved in muscle protein synthesis after a resistance training session performed in either the fasted or fed state. According to a randomized crossover study design, six young male subjects participated in two experimental sessions separated by 3 weeks. In each session, they performed a standardized resistance training. After the sessions, they received during a 4-h recovery period 6 ml/kg b.w. h of a solution containing carbohydrates (50 g/l), protein hydrolysate (33 g/l), and leucine (16.6 g/l). On one occasion, the resistance exercise session was performed after the intake of a carbohydrate-rich breakfast (B), whereas in the other session they remained fasted (F). Needle biopsies from m. vastus lateralis were obtained before (Rest), and 1 h (+1h) and 4 h (+4h) after exercise. Myogenin, MRF4, and MyoD1 mRNA contents were determined by RT-PCR. Phosphorylation of PKB (protein kinase B), GSK3, p70s6k (p70 ribosomal S6 kinase), eIF2B, eEF2 (eukaryotic elongation factor 2), ERK1/2, and p38 was measured via western blotting. Compared with F, the pre-exercise phosphorylation states of PKB and p70s6k were higher in B, whereas those of eIF2B and eEF2 were lower. During recovery, the phosphorylation state of p70s6k was lower in B than in F (p = 0.02). There were no differences in basal mRNA contents between B and F. However, compared with F at +1h, MyoD1 and MRF4 mRNA contents were lower in B (p < 0.05). Our results indicate that prior fasting may stimulate the intramyocellular anabolic response to ingestion of a carbohydrate/protein/leucine mixture following a heavy resistance training session.
Friday, January 22, 2010
Lean Gains blog
The leangains blog (leangains.blogspot.com) combines ADF with the paleo diet and weightlifting. Not sure how much science backs up his claims, but his results are impressive.
Wednesday, January 20, 2010
Retired Dieter blog
The Retired Dieter blogger used the Eat Stop Eat method of ADF (where the fasts only occur 2 days per week if I understand correctly) to lose a lot of weight and fat with great results. You can check out his story at retireddieter.com and his before and after pictures here
(http://retireddieter.com/2010/01/weight-loss-success-pictures/)
(http://retireddieter.com/2010/01/weight-loss-success-pictures/)
ADF and Exercise
Here a bunch of good posts from bradpilon.com (author of the book titled "Eat Stop Eat") exercising and fasting (the bottom line is, exercising when fasting is fine and in some cases even better than after having eaten!)
fasting exercise and blood sugar
http://bradpilon.com/healthy-ramblings/fasting-exercise-and-blood-sugar/
Here are two quick “Did you knows?” concerning fasting, exercise and blood sugar.
Did you know that it takes 30 to 60 minutes of running at 75% of your V02 max (for conditioned runners) to get your blood insulin levels down to the same level found in people who have been fasting for 23 hours? (Dohm LG 1986)
Did you know that when scientists studied people who exercised after fasting for 23 hours, their blood sugar levels were actually found to be slightly higher then when the same people exercised after a small meal? (Coyle EF 1985; Dohm LG 1986)
What this means to you- running at 75% of your VO2 max for as long as 70 minutes in well trained runners who had been fasting for 23 hours did not cause hypolgycemia (low blood sugar) So if you like exercising while you are fasted, this research suggests you don’t have to worry about hypoglycemia (as long as your exercise intensity isn’t way above these levels).
And it takes between 30 and 60 minutes of running at a VO2 of 75% to get the same insulin lowering effect as simply sitting around the house after fasting for 18-24 hours.
Two things to think about the next time you are fasting.
other great entries can be found at the links below:
Dohm GL, Beeker RT, Israel RG, Tapscott EB (1986) Metabolic responses to exercise after fasting. Journal of Applied Physiology, Vol 61, Issue 4 1363-1368
Abstract
Fasting before exercise increases fat utilization and lowers the rate of muscle glycogen depletion. Since a 24-h fast also depletes liver glycogen, we were interested in blood glucose homeostasis during exercise after fasting. An experiment was conducted with human subjects to determine the effect of fasting on blood metabolite concentrations during exercise. Nine male subjects ran (70% maximum O2 consumption) two counterbalanced trials, once fed and once after a 23-h fast. Plasma glucose was elevated by exercise in the fasted trial but there was no difference between fed and fasted during exercise. Lactate was significantly higher (P less than 0.05) in fasted than fed throughout the exercise bout. Fat mobilization and utilization appeared to be greater in the fasted trial as evidenced by higher plasma concentrations of free fatty acids, glycerol, and beta-hydroxybutyrate as well as lower respiratory exchange ratio in the fasted trial during the first 30 min of exercise. These results demonstrate that in humans blood glucose concentration is maintained at normal levels during exercise after fasting despite the depletion of liver glycogen. Homeostasis is probably maintained as a result of increased gluconeogenesis and decreased utilization of glucose in the muscle as a result of lowered pyruvate dehydrogenase activity.
fasting exercise and blood sugar
http://bradpilon.com/healthy-ramblings/fasting-exercise-and-blood-sugar/
Here are two quick “Did you knows?” concerning fasting, exercise and blood sugar.
Did you know that it takes 30 to 60 minutes of running at 75% of your V02 max (for conditioned runners) to get your blood insulin levels down to the same level found in people who have been fasting for 23 hours? (Dohm LG 1986)
Did you know that when scientists studied people who exercised after fasting for 23 hours, their blood sugar levels were actually found to be slightly higher then when the same people exercised after a small meal? (Coyle EF 1985; Dohm LG 1986)
What this means to you- running at 75% of your VO2 max for as long as 70 minutes in well trained runners who had been fasting for 23 hours did not cause hypolgycemia (low blood sugar) So if you like exercising while you are fasted, this research suggests you don’t have to worry about hypoglycemia (as long as your exercise intensity isn’t way above these levels).
And it takes between 30 and 60 minutes of running at a VO2 of 75% to get the same insulin lowering effect as simply sitting around the house after fasting for 18-24 hours.
Two things to think about the next time you are fasting.
other great entries can be found at the links below:
- fasting and exercise (http://bradpilon.com/healthy-ramblings/fasting-and-exercise/)
- fasting and atheltic performance (http://bradpilon.com/healthy-ramblings/fasting-and-athletic-performance/)
Dohm GL, Beeker RT, Israel RG, Tapscott EB (1986) Metabolic responses to exercise after fasting. Journal of Applied Physiology, Vol 61, Issue 4 1363-1368
Abstract
Fasting before exercise increases fat utilization and lowers the rate of muscle glycogen depletion. Since a 24-h fast also depletes liver glycogen, we were interested in blood glucose homeostasis during exercise after fasting. An experiment was conducted with human subjects to determine the effect of fasting on blood metabolite concentrations during exercise. Nine male subjects ran (70% maximum O2 consumption) two counterbalanced trials, once fed and once after a 23-h fast. Plasma glucose was elevated by exercise in the fasted trial but there was no difference between fed and fasted during exercise. Lactate was significantly higher (P less than 0.05) in fasted than fed throughout the exercise bout. Fat mobilization and utilization appeared to be greater in the fasted trial as evidenced by higher plasma concentrations of free fatty acids, glycerol, and beta-hydroxybutyrate as well as lower respiratory exchange ratio in the fasted trial during the first 30 min of exercise. These results demonstrate that in humans blood glucose concentration is maintained at normal levels during exercise after fasting despite the depletion of liver glycogen. Homeostasis is probably maintained as a result of increased gluconeogenesis and decreased utilization of glucose in the muscle as a result of lowered pyruvate dehydrogenase activity.
from fitnessspotlight.com: Benefits of Intermittent fasting
A good article on living the ADF life from fitnessspotlight.com
http://www.fitnessspotlight.com/2010/01/13/benefits-intermittent-fasting/
some highlights:
benefits of IF (ADF):
http://www.fitnessspotlight.com/2010/01/13/benefits-intermittent-fasting/
some highlights:
benefits of IF (ADF):
- Reduced blood glucose and insulin levels (markers of improved health)
- Increased fatty acid oxidation
- Maintenance of lean mass (muscle)
- Reduced inflammation
- Reduced oxidative damage
- Increased cellular stress resistance (esp of heart and brain)
- Decreased risks associated with degenerative diseases of aging (cancers, heart diseases, diabetes, Alzheimers)
Beneficial effects of intermittent fasting and caloric restriction on the cardiovascular and cerebrovascular systems.
Mattson MP, Wan R (2005) Beneficial effects of intermittent fasting and caloric restriction on the cardiovascular and cerebrovascular systems. J Nutr Biochem. 16(3):129-37.
Abstract
Intermittent fasting (IF; reduced meal frequency) and caloric restriction (CR) extend lifespan and increase resistance to age-related diseases in rodents and monkeys and improve the health of overweight humans. Both IF and CR enhance cardiovascular and brain functions and improve several risk factors for coronary artery disease and stroke including a reduction in blood pressure and increased insulin sensitivity. Cardiovascular stress adaptation is improved and heart rate variability is increased in rodents maintained on an IF or a CR diet. Moreover, rodents maintained on an IF regimen exhibit increased resistance of heart and brain cells to ischemic injury in experimental models of myocardial infarction and stroke. The beneficial effects of IF and CR result from at least two mechanisms--reduced oxidative damage and increased cellular stress resistance. Recent findings suggest that some of the beneficial effects of IF on both the cardiovascular system and the brain are mediated by brain-derived neurotrophic factor signaling in the brain. Interestingly, cellular and molecular effects of IF and CR on the cardiovascular system and the brain are similar to those of regular physical exercise, suggesting shared mechanisms. A better understanding of the cellular and molecular mechanisms by which IF and CR affect the blood vessels and heart and brain cells will likely lead to novel preventative and therapeutic strategies for extending health span.
Abstract
Intermittent fasting (IF; reduced meal frequency) and caloric restriction (CR) extend lifespan and increase resistance to age-related diseases in rodents and monkeys and improve the health of overweight humans. Both IF and CR enhance cardiovascular and brain functions and improve several risk factors for coronary artery disease and stroke including a reduction in blood pressure and increased insulin sensitivity. Cardiovascular stress adaptation is improved and heart rate variability is increased in rodents maintained on an IF or a CR diet. Moreover, rodents maintained on an IF regimen exhibit increased resistance of heart and brain cells to ischemic injury in experimental models of myocardial infarction and stroke. The beneficial effects of IF and CR result from at least two mechanisms--reduced oxidative damage and increased cellular stress resistance. Recent findings suggest that some of the beneficial effects of IF on both the cardiovascular system and the brain are mediated by brain-derived neurotrophic factor signaling in the brain. Interestingly, cellular and molecular effects of IF and CR on the cardiovascular system and the brain are similar to those of regular physical exercise, suggesting shared mechanisms. A better understanding of the cellular and molecular mechanisms by which IF and CR affect the blood vessels and heart and brain cells will likely lead to novel preventative and therapeutic strategies for extending health span.
Improvements in body fat distribution and circulating adiponectin by alternate-day fasting versus calorie restriction
Varady KA, Allister CA, Roohk DJ, Hellerstein MK (2009) Improvements in body fat distribution and circulating adiponectin by alternate-day fasting versus calorie restriction.J Nutr Biochem. Epub
Abstract
Calorie restriction (CR) and alternate-day fasting (ADF) beneficially affect several aspects of adipose tissue physiology, but direct comparisons between regimens have yet to be performed. The present study evaluated the effects of ADF versus CR on body fat distribution and circulating adiponectin levels and examined the kinetic mechanisms that underlie changes in fat distribution. Thirty female C57BL/6J mice were randomized to one of five groups for 4 weeks: (a) CR-25% (25% energy restriction daily), (b) ADF-75% (75% restriction on fast day), (c) ADF-85% (85% restriction on fast day), (d) ADF-100% (100% restriction on fast day) and (e) control (ad libitum fed). Body weights of the CR mice were lower than that of the ADF and control groups posttreatment. After 4 weeks of diet, the proportion of visceral fat decreased (P<.001) and the proportion of subcutaneous fat increased (P<.001) similarly in ADF and CR animals. Adiponectin increased (P<.05) by 62-86% in the ADF groups and by 69% in the CR group. Triglyceride (TG) synthesis and de novo lipogenesis were augmented (P<.05) in the subcutaneous fat pad of ADF and CR animals, relative to control. No differences in net lipolysis were observed, resulting in greater TG accumulation in the subcutaneous fat pad, with a shift in the ratio of TG between depots. These findings indicate that ADF (both modified and true) produces similar beneficial modulations in body fat distribution and adiponectin levels as daily CR
Abstract
Calorie restriction (CR) and alternate-day fasting (ADF) beneficially affect several aspects of adipose tissue physiology, but direct comparisons between regimens have yet to be performed. The present study evaluated the effects of ADF versus CR on body fat distribution and circulating adiponectin levels and examined the kinetic mechanisms that underlie changes in fat distribution. Thirty female C57BL/6J mice were randomized to one of five groups for 4 weeks: (a) CR-25% (25% energy restriction daily), (b) ADF-75% (75% restriction on fast day), (c) ADF-85% (85% restriction on fast day), (d) ADF-100% (100% restriction on fast day) and (e) control (ad libitum fed). Body weights of the CR mice were lower than that of the ADF and control groups posttreatment. After 4 weeks of diet, the proportion of visceral fat decreased (P<.001) and the proportion of subcutaneous fat increased (P<.001) similarly in ADF and CR animals. Adiponectin increased (P<.05) by 62-86% in the ADF groups and by 69% in the CR group. Triglyceride (TG) synthesis and de novo lipogenesis were augmented (P<.05) in the subcutaneous fat pad of ADF and CR animals, relative to control. No differences in net lipolysis were observed, resulting in greater TG accumulation in the subcutaneous fat pad, with a shift in the ratio of TG between depots. These findings indicate that ADF (both modified and true) produces similar beneficial modulations in body fat distribution and adiponectin levels as daily CR
Modified alternate-day fasting regimens reduce cell proliferation rates to a similar extent as daily calorie restriction in mice
Varady KA, Roohk DJ, McEvoy-Hein BK, Gaylinn BD, Thorner MO, Hellerstein MK (2008) Modified alternate-day fasting regimens reduce cell proliferation rates to a similar extent as daily calorie restriction in mice. FASEB J.(6):2090-6
Abstract
Calorie restriction (CR) and alternate-day fasting (ADF) reduce cancer risk and reduce cell proliferation rates. Whether modified ADF regimens (i.e., allowing a portion of energy needs to be consumed on the fast day) work, as well as true ADF or CR to reduce global cell proliferation rates, remains unresolved. Here, we measured the effects of true ADF, modified ADF, and daily CR on cell proliferation rates in mice. Thirty female C57BL/6J mice were randomized to one of five interventions for 4 wk: 1) CR-25% (25% reduction in daily energy intake), 2) ADF-75% (75% reduction on fast day), 3) ADF-85% (85% reduction on fast day), 4) ADF-100% (100% reduction on fast day), and 5) control (ad libitum intake). Body weights of the ADF groups did not differ from controls, whereas the CR-25% group weighed less than all other groups posttreatment. Epidermal cell proliferation decreased (P<0.01) by 29, 20, and 31% in the CR-25%, ADF-85% and ADF-100% groups, respectively, relative to controls. Proliferation rates of splenic T cells were reduced (P<0.01) by 37, 32, and 31% in the CR-25%, ADF-85%, and ADF-100% groups, respectively, and mammary epithelial cell proliferation was 70, 65, and 62% lower (P<0.01), compared with controls. Insulin-like growth factor-1 levels were reduced (P<0.05) in the CR-25% and ADF-100% groups only. In summary, modified ADF, allowing the consumption of 15% of energy needs on the restricted intake day, decreases global cell proliferation similarly as true ADF and daily CR without reducing body weight.
Abstract
Calorie restriction (CR) and alternate-day fasting (ADF) reduce cancer risk and reduce cell proliferation rates. Whether modified ADF regimens (i.e., allowing a portion of energy needs to be consumed on the fast day) work, as well as true ADF or CR to reduce global cell proliferation rates, remains unresolved. Here, we measured the effects of true ADF, modified ADF, and daily CR on cell proliferation rates in mice. Thirty female C57BL/6J mice were randomized to one of five interventions for 4 wk: 1) CR-25% (25% reduction in daily energy intake), 2) ADF-75% (75% reduction on fast day), 3) ADF-85% (85% reduction on fast day), 4) ADF-100% (100% reduction on fast day), and 5) control (ad libitum intake). Body weights of the ADF groups did not differ from controls, whereas the CR-25% group weighed less than all other groups posttreatment. Epidermal cell proliferation decreased (P<0.01) by 29, 20, and 31% in the CR-25%, ADF-85% and ADF-100% groups, respectively, relative to controls. Proliferation rates of splenic T cells were reduced (P<0.01) by 37, 32, and 31% in the CR-25%, ADF-85%, and ADF-100% groups, respectively, and mammary epithelial cell proliferation was 70, 65, and 62% lower (P<0.01), compared with controls. Insulin-like growth factor-1 levels were reduced (P<0.05) in the CR-25% and ADF-100% groups only. In summary, modified ADF, allowing the consumption of 15% of energy needs on the restricted intake day, decreases global cell proliferation similarly as true ADF and daily CR without reducing body weight.
Life extension by calorie restriction in humans
Everitt AV, Le Couteur DG (2007) Life extension by calorie restriction in humans Ann N Y Acad Sci. 1114:428-33
Abstract
Long-term reduction in energy intake in the diet (calorie restriction [CR]) extends the life of the laboratory rat by about 25%. However, in humans there are no life-long studies of CR, but only short-term trials which indicate that 20% CR acting over periods of 2-6 years is associated with reduced body weight, blood pressure, blood cholesterol, and blood glucose--risk factors for the major killer diseases of cardiovascular disease and diabetes. In addition, recent research has shown that CR for 6 months is able to improve biomarkers for longevity (deep body temperature and plasma insulin) and thus should increase life expectancy. The magnitude of the life-extension effect of CR in humans can only be estimated. The Okinawans, the longest-lived people on earth, consume 40% fewer calories than the Americans and live only 4 years longer. Similarly, women in United States consume 25% fewer calories than men and live 5 years longer. From the survival studies of overweight and obese people, it is estimated that long-term CR to prevent excessive weight gain could add only 3-13 years to life expectancy. Thus the effects of CR on human life extension are probably much smaller than those achieved by medical and public health interventions, which have extended life by about 30 years in developed countries in the 20th century, by greatly reducing deaths from infections, accidents, and cardiovascular disease
Abstract
Long-term reduction in energy intake in the diet (calorie restriction [CR]) extends the life of the laboratory rat by about 25%. However, in humans there are no life-long studies of CR, but only short-term trials which indicate that 20% CR acting over periods of 2-6 years is associated with reduced body weight, blood pressure, blood cholesterol, and blood glucose--risk factors for the major killer diseases of cardiovascular disease and diabetes. In addition, recent research has shown that CR for 6 months is able to improve biomarkers for longevity (deep body temperature and plasma insulin) and thus should increase life expectancy. The magnitude of the life-extension effect of CR in humans can only be estimated. The Okinawans, the longest-lived people on earth, consume 40% fewer calories than the Americans and live only 4 years longer. Similarly, women in United States consume 25% fewer calories than men and live 5 years longer. From the survival studies of overweight and obese people, it is estimated that long-term CR to prevent excessive weight gain could add only 3-13 years to life expectancy. Thus the effects of CR on human life extension are probably much smaller than those achieved by medical and public health interventions, which have extended life by about 30 years in developed countries in the 20th century, by greatly reducing deaths from infections, accidents, and cardiovascular disease
Effects of modified alternate-day fasting regimens on adipocyte size, triglyceride metabolism, and plasma adiponectin levels in mice
Varady KA, Roohk DJ, Loe YC, McEvoy-Hein BK, Hellerstein MK (2007) Effects of modified alternate-day fasting regimens on adipocyte size, triglyceride metabolism, and plasma adiponectin levels in mice. J Lipids Res 48(10):2212-9
Calorie restriction (CR) affects adipocyte function and reduces body weight. However, the effects of alternate-day fasting (ADF) on adipose biology remain unclear. This study examined the effects of ADF and modified ADF regimens on adipocyte size, triglyceride (TG) metabolism, and adiponectin levels in relation to changes in body weight and adipose mass. Twenty-four male C57BL/6J mice were randomized for 4 weeks among 1) ADF-25% (25% CR on fast day, ad libitum on alternate day), 2) ADF-50% (50% CR on fast day), 3) ADF-100% (100% CR on fast day), and 4) control (ad libitum). The body weight of ADF-100% mice was lower than that of the other groups (P < 0.005) after treatment. Adipose tissue weights did not change. Inguinal and epididymal fat cells were 35-50% smaller (P < 0.01) than those of controls in ADF-50% and ADF-100% animals after treatment. Net lipolysis was augmented (P < 0.05) in ADF-100% mice, and the contribution from glyceroneogenesis to alpha-glycerol phosphate increased in ADF-50% and ADF-100% mice, whereas fractional and absolute de novo lipogenesis also increased in ADF-50% and ADF-100% animals, consistent with an alternating feast-fast milieu. Plasma adiponectin levels were not affected. In summary, modified ADF (ADF-50%) and complete ADF (ADF-100%) regimens modulate adipocyte function, despite there being no change in body weight or adipose tissue weight in the former group.
Calorie restriction (CR) affects adipocyte function and reduces body weight. However, the effects of alternate-day fasting (ADF) on adipose biology remain unclear. This study examined the effects of ADF and modified ADF regimens on adipocyte size, triglyceride (TG) metabolism, and adiponectin levels in relation to changes in body weight and adipose mass. Twenty-four male C57BL/6J mice were randomized for 4 weeks among 1) ADF-25% (25% CR on fast day, ad libitum on alternate day), 2) ADF-50% (50% CR on fast day), 3) ADF-100% (100% CR on fast day), and 4) control (ad libitum). The body weight of ADF-100% mice was lower than that of the other groups (P < 0.005) after treatment. Adipose tissue weights did not change. Inguinal and epididymal fat cells were 35-50% smaller (P < 0.01) than those of controls in ADF-50% and ADF-100% animals after treatment. Net lipolysis was augmented (P < 0.05) in ADF-100% mice, and the contribution from glyceroneogenesis to alpha-glycerol phosphate increased in ADF-50% and ADF-100% mice, whereas fractional and absolute de novo lipogenesis also increased in ADF-50% and ADF-100% animals, consistent with an alternating feast-fast milieu. Plasma adiponectin levels were not affected. In summary, modified ADF (ADF-50%) and complete ADF (ADF-100%) regimens modulate adipocyte function, despite there being no change in body weight or adipose tissue weight in the former group.
Alternate-day fasting reduces global cell proliferation rates independently of dietary fat content in mice
Varady KA, Roohk DJ, Bruss M, Hellerstein MK (2009) Alternate-day fasting reduces global cell proliferation rates independently of dietary fat content in mice. Nutrition. 25(4):486-9
ABSTRACT
OBJECTIVE: Cell proliferation rates represent a central element in the promotional phase of carcinogenesis. Modified alternate-day fasting (ADF), i.e., a partial 24-h fast alternated with 24-h ad libitum feeding, reduces global cell proliferation rates on a low-fat (LF) diet. Because the majority of Americans consume a diet that is high in fat, testing the antiproliferative ability of ADF on a high-fat (HF) diet is important in terms of diet tolerability in humans. Accordingly, we examined the effects of 85% restriction on the fast day (ADF-85%) with an LF or HF background diet on proliferation rates of various tissues.
METHODS: In a 4-wk study, male C57BL/6J mice were randomized to one of three groups: 1) ADF-85%-LF, 2) ADF-85%-HF, or 3) control.
RESULTS: Body weights of the ADF mice were similar to that of controls throughout the study. A hyperphagic response (P < 0.001) was noted only in the ADF-85%-LF group ( approximately 55% more food consumed on the feed day than controls). No differences were noted for mean energy intake between ADF groups on feed or fast days. Equivalent reductions (P < 0.01) in epidermal, prostate, liver, and splenic T-cell proliferation rates were observed in both ADF groups versus controls. Plasma insulin-like growth factor-1 levels decreased (P < 0.05) similarly in both ADF groups. Insulin-like growth factor-1 mRNA levels were not affected by either treatment.
CONCLUSION: These findings indicate that ADF has an antiproliferative effect over a wide range of fat intakes, which may enhance adherence to ADF in humans.
ABSTRACT
OBJECTIVE: Cell proliferation rates represent a central element in the promotional phase of carcinogenesis. Modified alternate-day fasting (ADF), i.e., a partial 24-h fast alternated with 24-h ad libitum feeding, reduces global cell proliferation rates on a low-fat (LF) diet. Because the majority of Americans consume a diet that is high in fat, testing the antiproliferative ability of ADF on a high-fat (HF) diet is important in terms of diet tolerability in humans. Accordingly, we examined the effects of 85% restriction on the fast day (ADF-85%) with an LF or HF background diet on proliferation rates of various tissues.
METHODS: In a 4-wk study, male C57BL/6J mice were randomized to one of three groups: 1) ADF-85%-LF, 2) ADF-85%-HF, or 3) control.
RESULTS: Body weights of the ADF mice were similar to that of controls throughout the study. A hyperphagic response (P < 0.001) was noted only in the ADF-85%-LF group ( approximately 55% more food consumed on the feed day than controls). No differences were noted for mean energy intake between ADF groups on feed or fast days. Equivalent reductions (P < 0.01) in epidermal, prostate, liver, and splenic T-cell proliferation rates were observed in both ADF groups versus controls. Plasma insulin-like growth factor-1 levels decreased (P < 0.05) similarly in both ADF groups. Insulin-like growth factor-1 mRNA levels were not affected by either treatment.
CONCLUSION: These findings indicate that ADF has an antiproliferative effect over a wide range of fat intakes, which may enhance adherence to ADF in humans.
hypothesis: Pretreatment with alternate day modified fast will permit higher dose and frequency of cancer chemotherapy and better cure rates
Please note: This is a medical hypothesis and is currently not backed up by data from a clinical trial
Johnson JB, John S, Laub DR (2009) Pretreatment with alternate day modified fast will permit higher dose and frequency of cancer chemotherapy and better cure rates. Med Hypotheses.72(4):381-2
Abstract
It is established that calorie restriction (CR) increases the resistance of cells to various stressors such as oxidative damage, excitotoxins, mercury and acetaminophen. Alternate day feeding (ADF) may confer greater stress resistance than daily CR of 30% or 40%. A recent study in three strains of mouse showed that a fast of 48 or 60 h prevented toxic effects due to administration of doses 2-4 times the maximum human dose of etoposide, a chemotherapy agent which acts through increased oxidative stress. In addition, mice inoculated with neuroblastoma survived longer when pretreated with fasting, then given high dose etoposide, as well as not exhibiting toxicity. This increased survival was construed as evidence of differential stress resistance between normal and cancer cells, the cancer cells being only partially protected by the pretreatment fast. In clinical practice, increased differential stress resistance could lead to the use of much higher doses of chemotherapy agents, and in the absence of toxicity, make it possible to repeat the treatment to kill residual cancer cells. Humans are unlikely to comply with a total fast of longer than 24 or 48 h, which may be insufficient to activate the same gene expression process. Based on published data we estimate that an optimal time period for development of stress resistance is 2-3 weeks when alternate day feeding is employed. Our previously published experience suggests that 2-3 weeks of alternate day modified fast in which subjects eat ad libitum one day and <20% of one's estimated caloric requirement the next will confer a similar stress resistance. Compliance with this diet is high and greater maintenance of body weight is feasible. We hypothesize that a pretreatment of 2-3 weeks with the alternate day modified fast will improve outcomes in cancer chemotherapy, decreasing morbidity and raising cure rates.
Johnson JB, John S, Laub DR (2009) Pretreatment with alternate day modified fast will permit higher dose and frequency of cancer chemotherapy and better cure rates. Med Hypotheses.72(4):381-2
Abstract
It is established that calorie restriction (CR) increases the resistance of cells to various stressors such as oxidative damage, excitotoxins, mercury and acetaminophen. Alternate day feeding (ADF) may confer greater stress resistance than daily CR of 30% or 40%. A recent study in three strains of mouse showed that a fast of 48 or 60 h prevented toxic effects due to administration of doses 2-4 times the maximum human dose of etoposide, a chemotherapy agent which acts through increased oxidative stress. In addition, mice inoculated with neuroblastoma survived longer when pretreated with fasting, then given high dose etoposide, as well as not exhibiting toxicity. This increased survival was construed as evidence of differential stress resistance between normal and cancer cells, the cancer cells being only partially protected by the pretreatment fast. In clinical practice, increased differential stress resistance could lead to the use of much higher doses of chemotherapy agents, and in the absence of toxicity, make it possible to repeat the treatment to kill residual cancer cells. Humans are unlikely to comply with a total fast of longer than 24 or 48 h, which may be insufficient to activate the same gene expression process. Based on published data we estimate that an optimal time period for development of stress resistance is 2-3 weeks when alternate day feeding is employed. Our previously published experience suggests that 2-3 weeks of alternate day modified fast in which subjects eat ad libitum one day and <20% of one's estimated caloric requirement the next will confer a similar stress resistance. Compliance with this diet is high and greater maintenance of body weight is feasible. We hypothesize that a pretreatment of 2-3 weeks with the alternate day modified fast will improve outcomes in cancer chemotherapy, decreasing morbidity and raising cure rates.
Modified alternate-day fasting and cardioprotection
Varady KA, Hudak CS, Hellerstein MK. (2009) Modified alternate-day fasting and cardioprotection: relation to adipose tissue dynamics and dietary fat intake. Metabolism. 58(6):803-11.
Abstract
The relation between alternate-day fasting (ADF) and cardioprotection remains uncertain. In the present study, we examined the ability of modified ADF, with a low-fat (LF) vs high-fat (HF) background diet, to modulate adipose tissue physiology in a way that may protect against coronary heart disease. In a 4-week study, male C57BL/6 mice were randomized to 1 of 3 groups: (1) ADF-85%-LF (85% energy restriction on fast day, ad libitum fed on feed day, on an LF diet), (2) ADF-85%-HF (same protocol but HF diet), and (3) control (ad libitum fed). Throughout the study, body weight did not differ between ADF and control animals. Proportion of subcutaneous fat increased (P < .01), whereas the proportion of visceral fat decreased (P < .01), in both ADF groups. Triglyceride (TG) synthesis was augmented (P < .05) in subcutaneous fat, but remained unchanged in visceral fat. Adiponectin concentrations were elevated (P < .05), whereas leptin and resistin levels decreased (P < .05). Aortic vascular smooth muscle cell proliferation was reduced (P < .05) by 60% and 76% on the LF and HF diets, respectively. Plasma total cholesterol, TG, and free fatty acid concentrations also decreased (P < .05). In summary, modified ADF regimens alter adipose tissue physiology (ie, body fat distribution, TG metabolism, and adipokines) in a way that may protect against coronary heart disease. These beneficial effects were noted over a wide range of fat intake, suggesting that ADF may be protective even in the presence of HF diets.
Abstract
The relation between alternate-day fasting (ADF) and cardioprotection remains uncertain. In the present study, we examined the ability of modified ADF, with a low-fat (LF) vs high-fat (HF) background diet, to modulate adipose tissue physiology in a way that may protect against coronary heart disease. In a 4-week study, male C57BL/6 mice were randomized to 1 of 3 groups: (1) ADF-85%-LF (85% energy restriction on fast day, ad libitum fed on feed day, on an LF diet), (2) ADF-85%-HF (same protocol but HF diet), and (3) control (ad libitum fed). Throughout the study, body weight did not differ between ADF and control animals. Proportion of subcutaneous fat increased (P < .01), whereas the proportion of visceral fat decreased (P < .01), in both ADF groups. Triglyceride (TG) synthesis was augmented (P < .05) in subcutaneous fat, but remained unchanged in visceral fat. Adiponectin concentrations were elevated (P < .05), whereas leptin and resistin levels decreased (P < .05). Aortic vascular smooth muscle cell proliferation was reduced (P < .05) by 60% and 76% on the LF and HF diets, respectively. Plasma total cholesterol, TG, and free fatty acid concentrations also decreased (P < .05). In summary, modified ADF regimens alter adipose tissue physiology (ie, body fat distribution, TG metabolism, and adipokines) in a way that may protect against coronary heart disease. These beneficial effects were noted over a wide range of fat intake, suggesting that ADF may be protective even in the presence of HF diets.
Caloric restriction delays disease onset and mortality in rhesus monkeys
Please note: the owner of this blog does not support any scientific experimentation on primates (and in general is against the use of animals in biomedical experimentation). Nevertheless, I am posting this work out of respect for the monkeys who are living in biomedical research facilities and giving their lives unwillingly to science. This is perhaps a perfect example of how this research would have been more effective and conclusive had it been done in humans.
Colman RJ, Anderson RM, Johnson SC, Kastman EK, Kosmatka KJ, Beasley TM, Allison DB, Cruzen C, Simmons HA, Kemnitz JW, Weindruch R. (2009) Caloric restriction delays disease onset and mortality in rhesus monkeys. Science. 2009 Jul 10;325(5937):201-4.
Abstract
Caloric restriction (CR), without malnutrition, delays aging and extends life span in diverse species; however, its effect on resistance to illness and mortality in primates has not been clearly established. We report findings of a 20-year longitudinal adult-onset CR study in rhesus monkeys aimed at filling this critical gap in aging research. In a population of rhesus macaques maintained at the Wisconsin National Primate Research Center, moderate CR lowered the incidence of aging-related deaths. At the time point reported, 50% of control fed animals survived as compared with 80% of the CR animals. Furthermore, CR delayed the onset of age-associated pathologies. Specifically, CR reduced the incidence of diabetes, cancer, cardiovascular disease, and brain atrophy. These data demonstrate that CR slows aging in a primate species.
Colman RJ, Anderson RM, Johnson SC, Kastman EK, Kosmatka KJ, Beasley TM, Allison DB, Cruzen C, Simmons HA, Kemnitz JW, Weindruch R. (2009) Caloric restriction delays disease onset and mortality in rhesus monkeys. Science. 2009 Jul 10;325(5937):201-4.
Abstract
Caloric restriction (CR), without malnutrition, delays aging and extends life span in diverse species; however, its effect on resistance to illness and mortality in primates has not been clearly established. We report findings of a 20-year longitudinal adult-onset CR study in rhesus monkeys aimed at filling this critical gap in aging research. In a population of rhesus macaques maintained at the Wisconsin National Primate Research Center, moderate CR lowered the incidence of aging-related deaths. At the time point reported, 50% of control fed animals survived as compared with 80% of the CR animals. Furthermore, CR delayed the onset of age-associated pathologies. Specifically, CR reduced the incidence of diabetes, cancer, cardiovascular disease, and brain atrophy. These data demonstrate that CR slows aging in a primate species.
On the left is Canto (27) and on the right is Owen (29). Canto is fed with about 30% less calories than Owen (CR).
QOD
QOD is the only formalized version of ADF I have found and actually is how i first heard about ADF. Based on the peer-reviewed science I am not sure about how necessary the calories, protein and non-protein calories, etc are, but for some, I imagine that eating something makes the whole lifestyle easier and these then may be be good rules to follow. I personally try to fast (tea, water, maybe a diet redbull) on my fast days and if i really breakdown i just aim to be under 400 calories, no matter what those 500 calories are.
from eatQod.com
From the website: The QOD Diet™: Eating QOD is a way to lose weight gradually without pushing your body into starvation mode.Eating QOD allows you to eat pretty much what you want (within reason and without binging) every other day (ON days), so you don’t need to feel deprived. In between, during the OFF days, you need to limit food intake to 300-400 nonprotein calories, plus about 200 calories from protein, but your mineral intake (sodium, potassium, and calcium) should be kept constant.
from eatQod.com
From the website: The QOD Diet™: Eating QOD is a way to lose weight gradually without pushing your body into starvation mode.Eating QOD allows you to eat pretty much what you want (within reason and without binging) every other day (ON days), so you don’t need to feel deprived. In between, during the OFF days, you need to limit food intake to 300-400 nonprotein calories, plus about 200 calories from protein, but your mineral intake (sodium, potassium, and calcium) should be kept constant.
Alternate-day fasting in nonobese subjects
Heilbronn LK, Smith SR, Martin CK, Anton SD, Ravussin E. (2005) Alternate-day fasting in nonobese subjects: effects on body weight, body composition, and energy metabolism.Am J Clin Nutr.81(1):69-73
http://www.ajcn.org/cgi/content/full/81/1/69
Abstract
Background: Prolonged dietary restriction increases the life span in rodents. Some evidence suggests that alternate-day fasting may also prolong the life span.
Objective: Our goal was to determine whether alternate-day fasting is a feasible method of dietary restriction in nonobese humans and whether it improves known biomarkers of longevity.
Design: Nonobese subjects (8 men and 8 women) fasted every other day for 22 d. Body weight, body composition, resting metabolic rate (RMR), respiratory quotient (RQ), temperature, fasting serum glucose, insulin, free fatty acids, and ghrelin were assessed at baseline and after 21 d (12-h fast) and 22 d (36-h fast) of alternate-day fasting. Visual analogue scales were used to assess hunger weekly.
Results: Subjects lost 2.5 ± 0.5% of their initial body weight (P < 0.001) and 4 ± 1% of their initial fat mass (P < 0.001). Hunger increased on the first day of fasting and remained elevated (P < 0.001). RMR and RQ did not change significantly from baseline to day 21, but RQ decreased on day 22 (P < 0.001), which resulted in an average daily increase in fat oxidation of ≥15 g. Glucose and ghrelin did not change significantly from baseline with alternate-day fasting, whereas fasting insulin decreased 57 ± 4% (P < 0.001).
Conclusions: Alternate-day fasting was feasible in nonobese subjects, and fat oxidation increased. However, hunger on fasting days did not decrease, perhaps indicating the unlikelihood of continuing this diet for extended periods of time. Adding one small meal on a fasting day may make this approach to dietary restriction more acceptable.
http://www.ajcn.org/cgi/content/full/81/1/69
Abstract
Background: Prolonged dietary restriction increases the life span in rodents. Some evidence suggests that alternate-day fasting may also prolong the life span.
Objective: Our goal was to determine whether alternate-day fasting is a feasible method of dietary restriction in nonobese humans and whether it improves known biomarkers of longevity.
Design: Nonobese subjects (8 men and 8 women) fasted every other day for 22 d. Body weight, body composition, resting metabolic rate (RMR), respiratory quotient (RQ), temperature, fasting serum glucose, insulin, free fatty acids, and ghrelin were assessed at baseline and after 21 d (12-h fast) and 22 d (36-h fast) of alternate-day fasting. Visual analogue scales were used to assess hunger weekly.
Results: Subjects lost 2.5 ± 0.5% of their initial body weight (P < 0.001) and 4 ± 1% of their initial fat mass (P < 0.001). Hunger increased on the first day of fasting and remained elevated (P < 0.001). RMR and RQ did not change significantly from baseline to day 21, but RQ decreased on day 22 (P < 0.001), which resulted in an average daily increase in fat oxidation of ≥15 g. Glucose and ghrelin did not change significantly from baseline with alternate-day fasting, whereas fasting insulin decreased 57 ± 4% (P < 0.001).
Conclusions: Alternate-day fasting was feasible in nonobese subjects, and fat oxidation increased. However, hunger on fasting days did not decrease, perhaps indicating the unlikelihood of continuing this diet for extended periods of time. Adding one small meal on a fasting day may make this approach to dietary restriction more acceptable.
From the LATimes: Feast, fast and reduce risks
Originally published decemeber 10, 2007 in the LATimes.com
http://www.latimes.com/features/health/la-he-eat10dec10,1,883044.story
Feast, fast and reduce risks
An irregular eating cycle worked for ancient humans. Small studies show benefits in such calorie restriction.
By Susan Bowerman, Special to The Times
Our hunter-gatherer ancestors spent hours each day searching for food that was only intermittently available. They'd fast, and then they'd feast. These ancient humans developed a "thrifty" genotype that helped them adapt to these cycles of want and plenty.
Today, we carry this same genetic makeup with us, and several animal studies and few small human trials indicate that there may be, for us too, health benefits to alternate-day fasting -- a regimen that somewhat mimics the irregular and unpredictable food intake pattern on which our ancestors evolved.
Evidence has been accruing for some time that chronic calorie restriction, in which daily intake is reduced to between 60% and 85% of an individual's daily needs, appears to have significant health benefits. Such restriction has been shown to reduce risk factors for several chronic diseases in animals and humans and to increase life span in rats, mice, fish, flies, worms and yeast.
But the effects of alternate feast and fast days on body weight and health have only recently been explored.
In a study published in the American Journal of Clinical Nutrition in 2005, scientists at the Pennington Biomedical Research Center examined the effects of alternate-day fasting on heart disease risk in 16 subjects.
Subjects ate whatever they wanted on feast days but consumed only calorie-free beverages and sugarless gum on fast days. After three weeks, blood levels of triglycerides fell in men, but not in women. Women, but not men, experienced increases in "good," or HDL, cholesterol.
There was no clear explanation for the differing results between men and women, but the same group of scientists have observed other sex-specific effects. In a different report, they measured the rise in insulin and blood sugar levels in response to a meal before and after three weeks of alternate-day fasting.
Men -- but not women -- had increased insulin sensitivity so that they cleared sugar from the bloodstream more efficiently after three weeks on the regime, suggesting that alternate-day fasting may be more beneficial to men than women in reducing the risk of Type 2 diabetes.
Similar improvements in insulin sensitivity were observed after two weeks of alternate-day fasting in a small study of eight male subjects at the University of Copenhagen, published in the Journal of Applied Physiology in 2005.
The effects of alternate-day fasting on body weight differ according to the study (and none have been reported in overweight people). Men in the Copenhagen study maintained a stable body weight over the two week period -- but they were specifically instructed to attempt to do so.
In the Pennington study, subjects were informed that they would need to double their usual intake on non-fasting days in order to maintain their weight. But taking in enough food on the feasting days to avoid weight loss proved difficult. The participants lost about 2.5% of their initial weight and 4% of their initial fat mass.
All in all, the few human studies on alternate-day fasting have been small in size, short in duration and have lacked control groups so more studies are warranted. Still, the animal studies suggest that the effects of alternate-day fasting on chronic disease prevention are similar to those reported for chronic calorie restriction.
How such dietary calorie restriction may impart its benefits is not clear, but it may include increased resistance to stress, a reduction in free-radical production (which in turn reduces cellular damage) or the slowing of certain metabolic processes that might damage the body.
From a practical standpoint, it's unclear whether people could stick to an alternate-day fasting regimen for any length of time. Researchers have suggested that the regimen is easier than daily calorie restriction, but is it easy enough? Many subjects in the Pennington study reported feeling hungry and irritable on the days they fasted -- and that would probably limit the number of people who could sustain this pattern of eating for very long.
Anyone wishing to attempt either chronic or alternate-day calorie restriction needs to remember that consuming nutrient-dense foods is key. There are no extra calories to spare, so every bite of food needs to be packed with nutrition.
But a carefully planned diet based on vegetables and fruits, lean proteins, a few whole grains and small portions -- rather than a continuous and abundant food intake -- may be a better nutritional match for those "thrifty" genes.
Susan Bowerman is a registered dietitian and assistant director of the UCLA Center for Human Nutrition.
http://www.latimes.com/features/health/la-he-eat10dec10,1,883044.story
Feast, fast and reduce risks
An irregular eating cycle worked for ancient humans. Small studies show benefits in such calorie restriction.
By Susan Bowerman, Special to The Times
Our hunter-gatherer ancestors spent hours each day searching for food that was only intermittently available. They'd fast, and then they'd feast. These ancient humans developed a "thrifty" genotype that helped them adapt to these cycles of want and plenty.
Today, we carry this same genetic makeup with us, and several animal studies and few small human trials indicate that there may be, for us too, health benefits to alternate-day fasting -- a regimen that somewhat mimics the irregular and unpredictable food intake pattern on which our ancestors evolved.
Evidence has been accruing for some time that chronic calorie restriction, in which daily intake is reduced to between 60% and 85% of an individual's daily needs, appears to have significant health benefits. Such restriction has been shown to reduce risk factors for several chronic diseases in animals and humans and to increase life span in rats, mice, fish, flies, worms and yeast.
But the effects of alternate feast and fast days on body weight and health have only recently been explored.
In a study published in the American Journal of Clinical Nutrition in 2005, scientists at the Pennington Biomedical Research Center examined the effects of alternate-day fasting on heart disease risk in 16 subjects.
Subjects ate whatever they wanted on feast days but consumed only calorie-free beverages and sugarless gum on fast days. After three weeks, blood levels of triglycerides fell in men, but not in women. Women, but not men, experienced increases in "good," or HDL, cholesterol.
There was no clear explanation for the differing results between men and women, but the same group of scientists have observed other sex-specific effects. In a different report, they measured the rise in insulin and blood sugar levels in response to a meal before and after three weeks of alternate-day fasting.
Men -- but not women -- had increased insulin sensitivity so that they cleared sugar from the bloodstream more efficiently after three weeks on the regime, suggesting that alternate-day fasting may be more beneficial to men than women in reducing the risk of Type 2 diabetes.
Similar improvements in insulin sensitivity were observed after two weeks of alternate-day fasting in a small study of eight male subjects at the University of Copenhagen, published in the Journal of Applied Physiology in 2005.
The effects of alternate-day fasting on body weight differ according to the study (and none have been reported in overweight people). Men in the Copenhagen study maintained a stable body weight over the two week period -- but they were specifically instructed to attempt to do so.
In the Pennington study, subjects were informed that they would need to double their usual intake on non-fasting days in order to maintain their weight. But taking in enough food on the feasting days to avoid weight loss proved difficult. The participants lost about 2.5% of their initial weight and 4% of their initial fat mass.
All in all, the few human studies on alternate-day fasting have been small in size, short in duration and have lacked control groups so more studies are warranted. Still, the animal studies suggest that the effects of alternate-day fasting on chronic disease prevention are similar to those reported for chronic calorie restriction.
How such dietary calorie restriction may impart its benefits is not clear, but it may include increased resistance to stress, a reduction in free-radical production (which in turn reduces cellular damage) or the slowing of certain metabolic processes that might damage the body.
From a practical standpoint, it's unclear whether people could stick to an alternate-day fasting regimen for any length of time. Researchers have suggested that the regimen is easier than daily calorie restriction, but is it easy enough? Many subjects in the Pennington study reported feeling hungry and irritable on the days they fasted -- and that would probably limit the number of people who could sustain this pattern of eating for very long.
Anyone wishing to attempt either chronic or alternate-day calorie restriction needs to remember that consuming nutrient-dense foods is key. There are no extra calories to spare, so every bite of food needs to be packed with nutrition.
But a carefully planned diet based on vegetables and fruits, lean proteins, a few whole grains and small portions -- rather than a continuous and abundant food intake -- may be a better nutritional match for those "thrifty" genes.
Susan Bowerman is a registered dietitian and assistant director of the UCLA Center for Human Nutrition.
Reuters Health:Fasting Every Other Day Cuts Weight, Ups Crankiness
originally published February 1st, 2005 via womenfitness.net
http://www.womenfitness.net/news/wt_managment/fasting_every_other_day.htm
Fasting Every Other Day Cuts Weight, Ups Crankiness
NEW YORK (Reuters Health) - Shunning food every other day may be a feasible way to slash calories -- if you and those around you don't mind the crankiness that comes with it, according to researchers.
Their study of 16 nonobese men and women looked at the effects of alternate-day fasting, an eating plan that interspersed fasting days with "feasting" days that allowed participants to eat as much as they wanted.
The researchers were interested in whether food deprivation every second day would be easier on people than counting calories on a daily basis, lead author Dr. Eric Ravussin told Reuters Health.
They found that the diet plan was indeed "feasible," at least for the duration of the 3-week study. Overall, the men and women lost an average of 5 pounds, while shedding some body fat.
On the other hand, Ravussin said, "most people were not happy" -- a major problem being the crankiness that erupted on the fasting days and did not abate over the 3 weeks.
Ravussin and his colleagues at the Pennington Biomedical Research Center in Baton Rouge, Louisiana, report the findings in the American Journal of Clinical Nutrition.
Uncovering the most tolerable ways for people to cut calories is not just a matter of trimming waistlines. A number of studies, Ravussin explained, have now shown that calorie restriction can extend the lives of everything from yeast and worms to rodents and, possibly, monkeys.
There are a number of theories on why limiting food might make for a longer, healthier life. One idea, Ravussin noted, is that slowing the rate of metabolism reduces the generation of oxygen free radicals, potentially cell-damaging molecules that are a normal byproduct of the metabolic process.
No one knows if calorie counting can extend human life as it does for some animals. Ravussin and his colleagues are currently conducting a trial, sponsored by the National Institutes of Health, which is examining how long-term dietary restriction affects people's health and longevity.
Studying dietary restriction in people is, of course, far more complicated than studying it in lab rats. The ongoing trial is investigating how calorie cutting affects "biomarkers of longevity" in people, such as levels of blood sugar and insulin, a hormone key in regulating blood sugar.
The trial is testing several methods of dietary restriction -- from pure calorie cutting to burning extra calories through exercise -- to see which are most viable.
In the current study, Ravussin's team evaluated the effects of alternate-day fasting, an approach not included in that trial. They wanted to see if the eating plan was feasible and whether it influenced biomarkers of longevity, as well as participants' weight and metabolism.
As mentioned, every other day for 3 weeks the men and women subsisted on calorie-free beverages and sugarless gum. On the days in between, they ate whatever they wanted.
According to Ravussin, participants were not able to "make up" for what they didn't eat on fasting days, and consequently, they generally lost a few pounds and some fat mass. In addition, their insulin levels declined by an average of about 57 percent.
However, the researchers also found that many participants said they were irritable on food-free days, and they did not appear to get used to having an empty stomach every other day.
Calorie restriction, Ravussin noted, is the only behavior that has so far been shown to prolong life. "There is a ton of data suggesting that this is the only way to the 'fountain of youth', if you want," he said. If the current findings are any indication, the researcher added, alternate-day fasting may not be the easiest path to that fountain.
SOURCE: American Journal of Clinical Nutrition, January 2005.
http://www.womenfitness.net/news/wt_managment/fasting_every_other_day.htm
Fasting Every Other Day Cuts Weight, Ups Crankiness
NEW YORK (Reuters Health) - Shunning food every other day may be a feasible way to slash calories -- if you and those around you don't mind the crankiness that comes with it, according to researchers.
Their study of 16 nonobese men and women looked at the effects of alternate-day fasting, an eating plan that interspersed fasting days with "feasting" days that allowed participants to eat as much as they wanted.
The researchers were interested in whether food deprivation every second day would be easier on people than counting calories on a daily basis, lead author Dr. Eric Ravussin told Reuters Health.
They found that the diet plan was indeed "feasible," at least for the duration of the 3-week study. Overall, the men and women lost an average of 5 pounds, while shedding some body fat.
On the other hand, Ravussin said, "most people were not happy" -- a major problem being the crankiness that erupted on the fasting days and did not abate over the 3 weeks.
Ravussin and his colleagues at the Pennington Biomedical Research Center in Baton Rouge, Louisiana, report the findings in the American Journal of Clinical Nutrition.
Uncovering the most tolerable ways for people to cut calories is not just a matter of trimming waistlines. A number of studies, Ravussin explained, have now shown that calorie restriction can extend the lives of everything from yeast and worms to rodents and, possibly, monkeys.
There are a number of theories on why limiting food might make for a longer, healthier life. One idea, Ravussin noted, is that slowing the rate of metabolism reduces the generation of oxygen free radicals, potentially cell-damaging molecules that are a normal byproduct of the metabolic process.
No one knows if calorie counting can extend human life as it does for some animals. Ravussin and his colleagues are currently conducting a trial, sponsored by the National Institutes of Health, which is examining how long-term dietary restriction affects people's health and longevity.
Studying dietary restriction in people is, of course, far more complicated than studying it in lab rats. The ongoing trial is investigating how calorie cutting affects "biomarkers of longevity" in people, such as levels of blood sugar and insulin, a hormone key in regulating blood sugar.
The trial is testing several methods of dietary restriction -- from pure calorie cutting to burning extra calories through exercise -- to see which are most viable.
In the current study, Ravussin's team evaluated the effects of alternate-day fasting, an approach not included in that trial. They wanted to see if the eating plan was feasible and whether it influenced biomarkers of longevity, as well as participants' weight and metabolism.
As mentioned, every other day for 3 weeks the men and women subsisted on calorie-free beverages and sugarless gum. On the days in between, they ate whatever they wanted.
According to Ravussin, participants were not able to "make up" for what they didn't eat on fasting days, and consequently, they generally lost a few pounds and some fat mass. In addition, their insulin levels declined by an average of about 57 percent.
However, the researchers also found that many participants said they were irritable on food-free days, and they did not appear to get used to having an empty stomach every other day.
Calorie restriction, Ravussin noted, is the only behavior that has so far been shown to prolong life. "There is a ton of data suggesting that this is the only way to the 'fountain of youth', if you want," he said. If the current findings are any indication, the researcher added, alternate-day fasting may not be the easiest path to that fountain.
SOURCE: American Journal of Clinical Nutrition, January 2005.
Musing Forces blog
Musing Forces blog is a first person account of one woman's alternate day fasting experiences. Great for people just starting off with ADF and wanting to know what to expect.
There are also great alternate day fasting links and resources on this blog.
http://musingforces.blogspot.com/
There are also great alternate day fasting links and resources on this blog.
http://musingforces.blogspot.com/
From ScienceNews.org: Possible anticancer power in fasting every other day
originally published January 26th, 2009 on ScienceNews.org
http://www.sciencenews.org/view/generic/id/40242/title/Possible_anticancer_power_in_fasting_every_other_day
http://www.sciencenews.org/view/generic/id/40242/title/Possible_anticancer_power_in_fasting_every_other_day
Possible anticancer power in fasting every other day
When mice ate as important as what they ate in reducing cell division linked to cancer
Fasting every other day reduces some hallmarks of cancer in mice, even when the mice voraciously consume high-fat food between fasts, a study in an upcoming Nutrition shows.
Scientists have known for decades that eating fewer calories — roughly 25 to 50 percent less than recommended — extends life span in animals ranging from worms to dogs. But, “caloric restriction on a daily basis is very hard,” says Eric Ravussin, a physiologist at the Pennington Biomedical Research Center in Baton Rouge, La., who studies caloric restriction.
Last year, researchers including Krista Varady, then of the University of California, Berkeley, published a study suggesting that a less drastic version of caloric restriction provides a constellation of health benefits in mice. Called alternate-day fasting, the regimen of eating as much food, low-fat in this study, as one wants one day but fasting the next confers some of the same anticancer benefits as just cutting calories at a constant rate, the team found.
But for people, eating a low-fat diet one day and fasting the next is still challenging. Varady and her colleagues wanted to know whether the diet could be made easier to swallow and still provide similar benefits.
In the new study, Varady and other researchers compared mice who fasted every other day, both on high-fat and low-fat diets, to mice that didn’t fast but instead ate a low-fat diet every day. The mice on the ultimate yo-yo diet ate high-fat food, in which 45 percent of the calories came from fat — comparable, Varady says, to human diets of fast food and processed food.
On the fasting days, mice were fed 15 percent of their required calories from either the high- or low-fat food.
The results were surprising, says Varady. Mice that ate the rodent equivalent of Big Macs every other day showed the same anticancer benefits of fasting as the mice that ate the low-fat diet every other day. High rates of cell division — a key feature of cancer — were lower in the mice who fasted every other day than in mice that had not fasted. Mice who fasted every other day also had reduced levels of IGF-1, a protein that induces cell growth and has been linked to cancer.
The new study on mice is the “next installment in a systematic and interesting series of studies” from the researchers, comments James Johnson, a doctor affiliated with the Louisiana State University Health Sciences Center and studies alternate-day fasting in humans.
The option to eat high-fat meals while fasting every other day may make people more likely to stick with the demanding diet regimen, researchers say. To date, only three small studies have examined the effects of alternate-day fasting on people, says Varady, now at the University of Illinois in Chicago.
She says the next step is to see whether an unrestricted high-fat diet one day and a small amount of food the next will confer the same health benefits in humans as it does in mice. Varady and her colleagues are currently conducting a study to test whether humans are able to stick with such a diet. Preliminary data suggest that they can.
“The alternate diet has a lot of potential,” comments Valter Longo, a University of Southern California in Los Angeles researcher who studies aging. But, he adds, “I seriously doubt that very many people would adopt it because it is very tough to do regularly.”
Ravussin knows the difficulty firsthand. When he attempted alternate-day fasting himself, he reported feeling very irritable and hungry. “My wife told me, ‘Don’t do it again.’ ”
Alternate-day fasting and chronic disease prevention: a review of human and animal trials
Varady KA and Hellerstein MK (2007) Alternate-day fasting and chronic disease prevention: a review of human and animal trials. American Journal of Clinical Nutrition, Vol. 86, No. 1, 7-13, July 2007
http://www.ajcn.org/cgi/content/full/86/1/7
Abstract
Calorie restriction (CR) and alternate-day fasting (ADF) represent 2 different forms of dietary restriction. Although the effects of CR on chronic disease prevention were reviewed previously, the effects of ADF on chronic disease risk have yet to be summarized. Accordingly, we review here animal and human evidence concerning ADF and the risk of certain chronic diseases, such as type 2 diabetes, cardiovascular disease, and cancer. We also compare the magnitude of risk reduction resulting from ADF with that resulting from CR. In terms of diabetes risk, animal studies of ADF find lower diabetes incidence and lower fasting glucose and insulin concentrations, effects that are comparable to those of CR. Human trials to date have reported greater insulin-mediated glucose uptake but no effect on fasting glucose or insulin concentrations. In terms of cardiovascular disease risk, animal ADF data show lower total cholesterol and triacylglycerol concentrations, a lower heart rate, improved cardiac response to myocardial infarction, and lower blood pressure. The limited human evidence suggests higher HDL-cholesterol concentrations and lower triacylglycerol concentrations but no effect on blood pressure. In terms of cancer risk, there is no human evidence to date, yet animal studies found decreases in lymphoma incidence, longer survival after tumor inoculation, and lower rates of proliferation of several cell types. The findings in animals suggest that ADF may effectively modulate several risk factors, thereby preventing chronic disease, and that ADF may modulate disease risk to an extent similar to that of CR. More research is required to establish definitively the consequences of ADF.
http://www.ajcn.org/cgi/content/full/86/1/7
Abstract
Calorie restriction (CR) and alternate-day fasting (ADF) represent 2 different forms of dietary restriction. Although the effects of CR on chronic disease prevention were reviewed previously, the effects of ADF on chronic disease risk have yet to be summarized. Accordingly, we review here animal and human evidence concerning ADF and the risk of certain chronic diseases, such as type 2 diabetes, cardiovascular disease, and cancer. We also compare the magnitude of risk reduction resulting from ADF with that resulting from CR. In terms of diabetes risk, animal studies of ADF find lower diabetes incidence and lower fasting glucose and insulin concentrations, effects that are comparable to those of CR. Human trials to date have reported greater insulin-mediated glucose uptake but no effect on fasting glucose or insulin concentrations. In terms of cardiovascular disease risk, animal ADF data show lower total cholesterol and triacylglycerol concentrations, a lower heart rate, improved cardiac response to myocardial infarction, and lower blood pressure. The limited human evidence suggests higher HDL-cholesterol concentrations and lower triacylglycerol concentrations but no effect on blood pressure. In terms of cancer risk, there is no human evidence to date, yet animal studies found decreases in lymphoma incidence, longer survival after tumor inoculation, and lower rates of proliferation of several cell types. The findings in animals suggest that ADF may effectively modulate several risk factors, thereby preventing chronic disease, and that ADF may modulate disease risk to an extent similar to that of CR. More research is required to establish definitively the consequences of ADF.
From "The Independant": Feast & Famine: The Alternate Day Diet
Here is an article from the Indpendant I found wholly unconvincing. The nutritionists interviewed for this article warn against "unhealthy" and "unbalanced" eating habits and yet there is no data to support any of their claims. On the other hand, studies on the health and weight loss benefits of ADF do exist. The journalist's own personal account of her time on ADF (eat anything you want on one day and limited calories on the next) is only one of several ADF variants and i think few people actually following ADF, binge as she did on their eating days. Nevertheless she still lost 2 lbs which is a pretty incredible result especially for someone who didn't consider herself overweight to start with!
originally published Tuesday, 15 April 2008 in the Independant
http://www.independent.co.uk/life-style/health-and-families/healthy-living/feast--famine-the-alternate-day-diet-808940.html
Feast & Famine: The Alternate Day Diet
This promises fantastic weight-loss results - but to many nutritionists, it's heresy. Rachel Shields puts it to the test
It wasn't that long ago that we braved bad breath and high blood pressure on the Atkins, ignoring health warnings - and common sense - in our desperation to shed pounds. Recently, however, it has looked like the days of dangerous fad diets were over, replaced by a healthier, more sustainable attitude to weight loss. Sadly the growing buzz around a new eating plan suggests otherwise.
Dubbed "part-time anorexia" for the drastic eating pattern of bingeing and starving that it recommends, the Alternate Day Diet is the brainchild of plastic surgeon James B Johnson. Criticised by health professionals as physically and mentally damaging, the diet encourages followers to eat "whatever they want" every other day, but virtually nothing the next.
The idea of a diet in which absolutely no food is off limits is understandably seductive, particularly for those long-term dieters that have spent years ignoring the bread basket and turning down pudding. The gruelling diet days - also known as "down days" - are less appealing. On these days, followers must limit themselves to a meagre 300 to 500 calories. Given that the average woman needs 2,000 calories a day, and the average man 2,500, this seems woefully inadequate.
During the first few weeks of the diet, Dr Johnson advises dieters to consume their down-day calories in the form of protein shakes, to be sipped throughout the day.
Anna Denney, a nutrition scientist at the British Nutrition Foundation, says: "You will definitely feel the physical effects if you only eat 300 calories in a day - you'll probably feel hungry, sick and dizzy. Psychologically it is going to be challenging too - one day you are telling people to have no self-control, the next they have to have a will of iron."
So, imagine stuffing yourself with biscuits, chips, steak, wine, chocolate... every forbidden food, and then "balancing" it out by fasting the next day. If you think that this sounds more like an eating disorder than a diet plan, you are not alone. Dr Johnson's diet has already captured the attention of pro-anorexia websites and - even more worryingly - teen internet message boards, on which girls as young as 12 swap health and beauty tips.
There are notable parallels between the Alternate Day Diet and bulimia - a condition that has affected many influential celebrities, including Britney Spears and Geri Halliwell, in which sufferers deprive themselves of food, and then overeat to compensate - and experts have expressed concerns that the diet may encourage unhealthy eating patterns.
"A disordered eating pattern such as this is obviously not to be recommended," says Mary George of the eating disorder charity Beat. "Depriving the body of regular nutrients in this way over a period of time could lead to long-term harm and possibly take someone down the path to a full-blown eating disorder."
Instances of eating disorders in the UK have more than doubled since the 1960s, with binge-and-purge eating patterns becoming more and more common. An estimated 3 per cent of females in Britain between the ages of 10 and 20 suffer from problemsrelated to a binge-and-purge diet.
While it must be remembered that eating disorders are a mental illness, not just "a diet gone wrong", health professionals believe that countless people are engaged in a less severe, but still extremely damaging, cycle of "binge and starve" eating. This cycle often begins when an individual attempts to restrict their food intake order to lose weight, but then "breaks" their diet and overeats due to feelings of deprivation and hunger.
Dr Graham McGregor, professor of cardiovascular medicine at St George's Hospital, London, says: "We did studies on medical students in which we saw that people who fasted would get so hungry that they'd then binge on the worst possible foods. It is a see-saw effect. You also get lots of salt one day and very little the next, which has a dramatic effect on the body. It is a totally unphysiological thing to do."
Despite the stresses that such extreme eating patterns place on the human body - overloading the digestive system, raising blood pressure and causing dehydration - Dr McGregor believes that this is now extremely widespread.
"Most women starve and binge to an extent," he says. "They want to lose weight, so they eat very little, then they get really hungry and when their boyfriend takes them out to dinner, they eat a huge meal."
While Dr Johnson, who is based in New Orleans, admits that extreme diets can trigger or exacerbate eating disorders, he denies that his new diet encourages this sort of unhealthy behaviour. He insists that the small amounts of food allowed on down days are enough to prevent dieters experiencing the extreme hunger that could lead to gorging on up days.
"I haven't seen anybody on this diet who goes to extremes and binges or starves," says Dr Johnson. "I don't recommend going without food completely, because if you starve all day then that can trigger a loss of control and you'll be non-stop eating." He believes that the diet actually regulates the appetite, meaning that if people have eaten lots one day, they will be less hungry the next.
Denney disagrees. "Eating lots one day and little the next doesn't teach people the importance of balance in their diet," she argues. "Young people in particular need to learn to regulate what they eat, and a day of gluttony followed by a day of starvation won't help them to do this."
Dr Johnson's book claims that the roller-coaster calorie consumption of alternate day eating is not only easy to follow, but also triggers physical effects that help followers to lose weight. While most low-calorie diets slow down the metabolism, reducing the rate at which the body burns calories and thus hindering weight loss, Dr Johnson insists that his diet works to speed up the metabolism, tricking the body into burning up more calories than before.
"There was a study at the Pennington Biomedical Research Institute where volunteers ate nothing at all every other day for three weeks. They lost 2 per cent of their body weight over that time, but their resting energy expenditure didn't change. The alternating days system prevented the metabolic rate from dropping."
The idea for the diet came about after Dr Johnson, who had struggled with his own weight, spotted a scientific study in the American Journal of Clinical Nutrition which suggested that mice that were fed only every other day experienced significant weight loss and other health benefits.
"When I read it, it struck me like a thunderbolt," says Dr Johnson. "It just made sense. Personally, I knew that I couldn't do 'not eating anything' on alternate days, but I could cope with consuming about 20 per cent of my normal daily intake."
In the clinical trials Dr Johnson conducted in 2004, he said that volunteers lost on average 8 per cent of their body weight over an 8-week period, and experienced other health benefits.
"I was sure that the diet had benefits other than losing weight, so I picked some asthma sufferers to take part in the trial," adds Dr Johnson. "They showed dramatic improvements in their peak flow (how fast you can blow air in and out of your lungs). There is a clear biological hypothesis for this - the very low calorie intake on the down day triggers an anti-inflammatory gene, which improves the asthma."
Johnson believes that his diet can also help to lower blood pressure and improve conditions such as arthritis, as well as reducing levels of potentially harmful free radicals in the bloodstream - claims that have already met with some scepticism.
"I'm unaware of any evidence that supports this hypothesis," insists Dr McGregor. "I mean, what happened to the Atkins? People who try diets like this might lose weight at first - because they are watching what they are eating - but they'll put it back on again."
While doctors may be right to question such a radical diet, Dr Johnson's plan does seem to have tapped into something. Internet message boards are heaving with glowing testimonials from thousands of people already subscribing to the schizophrenic eating patterns. Oddly, perhaps it is precisely because it is so extreme that Dr Johnson's "feast and famine" approach appeals to the dieters of 2008 - in a culture of size zeros and rising obesity levels, it doesn't seem all that crazy.
Day by day: the diet
I'm not desperate to lose weight, but with summer on the way, the thought of baring arms, legs or anything in between is enough to make me wish that the needle on the scales hovered a few lines lower. I decide to start on an "up" day, meaning that I can eat anything I want. Turns out, I want a lot of food, most of it fattening.
My usual breakfast of porridge or toast is eschewed in favour of a cinnamon roll and two pains au chocolat, sushi lunch swapped for a giant panini and crisps, and modest dinner replaced with an Indian banquet, followed by a box of chocolates. I could get used to this diet.
I wake up the next day nursing a "food hangover", complete with dry mouth, gurgling stomach and slightly sick feeling. If this continues, avoiding food should be a doddle.
Needless to say, it doesn't last. At 10.30am I can smell toast, and it's a damn sight more appealing then the strawberry meal-replacement shake Dr Johnson recommends I "sip throughout the day". By 4pm, I'm grumpy, tired, shaky, and more than a little hungry.
I'm allowed a meal in the evening, as long as it is less than 250 calories, and leaf through Dr Johnson's recipes in search of something edible. No such luck. I settle for a broccoli omelette, which wouldn't fill the gap in a hollow tooth. I sneak in a cracker with jam before bed, which sends me over my calorie limit. This is nowhere near as fun as yesterday.
The cycle continues for the rest of the week - I feel too full one day, and too hungry the next. When I finally step on the scales, I find I have lost 2lbs. I'm pleasantly surprised, but I won't be sticking with it. Dr Johnson is right about one thing - it doesn't feel like a diet. Shame it doesn't feel great either.
originally published Tuesday, 15 April 2008 in the Independant
http://www.independent.co.uk/life-style/health-and-families/healthy-living/feast--famine-the-alternate-day-diet-808940.html
Feast & Famine: The Alternate Day Diet
This promises fantastic weight-loss results - but to many nutritionists, it's heresy. Rachel Shields puts it to the test
It wasn't that long ago that we braved bad breath and high blood pressure on the Atkins, ignoring health warnings - and common sense - in our desperation to shed pounds. Recently, however, it has looked like the days of dangerous fad diets were over, replaced by a healthier, more sustainable attitude to weight loss. Sadly the growing buzz around a new eating plan suggests otherwise.
Dubbed "part-time anorexia" for the drastic eating pattern of bingeing and starving that it recommends, the Alternate Day Diet is the brainchild of plastic surgeon James B Johnson. Criticised by health professionals as physically and mentally damaging, the diet encourages followers to eat "whatever they want" every other day, but virtually nothing the next.
The idea of a diet in which absolutely no food is off limits is understandably seductive, particularly for those long-term dieters that have spent years ignoring the bread basket and turning down pudding. The gruelling diet days - also known as "down days" - are less appealing. On these days, followers must limit themselves to a meagre 300 to 500 calories. Given that the average woman needs 2,000 calories a day, and the average man 2,500, this seems woefully inadequate.
During the first few weeks of the diet, Dr Johnson advises dieters to consume their down-day calories in the form of protein shakes, to be sipped throughout the day.
Anna Denney, a nutrition scientist at the British Nutrition Foundation, says: "You will definitely feel the physical effects if you only eat 300 calories in a day - you'll probably feel hungry, sick and dizzy. Psychologically it is going to be challenging too - one day you are telling people to have no self-control, the next they have to have a will of iron."
So, imagine stuffing yourself with biscuits, chips, steak, wine, chocolate... every forbidden food, and then "balancing" it out by fasting the next day. If you think that this sounds more like an eating disorder than a diet plan, you are not alone. Dr Johnson's diet has already captured the attention of pro-anorexia websites and - even more worryingly - teen internet message boards, on which girls as young as 12 swap health and beauty tips.
There are notable parallels between the Alternate Day Diet and bulimia - a condition that has affected many influential celebrities, including Britney Spears and Geri Halliwell, in which sufferers deprive themselves of food, and then overeat to compensate - and experts have expressed concerns that the diet may encourage unhealthy eating patterns.
"A disordered eating pattern such as this is obviously not to be recommended," says Mary George of the eating disorder charity Beat. "Depriving the body of regular nutrients in this way over a period of time could lead to long-term harm and possibly take someone down the path to a full-blown eating disorder."
Instances of eating disorders in the UK have more than doubled since the 1960s, with binge-and-purge eating patterns becoming more and more common. An estimated 3 per cent of females in Britain between the ages of 10 and 20 suffer from problemsrelated to a binge-and-purge diet.
While it must be remembered that eating disorders are a mental illness, not just "a diet gone wrong", health professionals believe that countless people are engaged in a less severe, but still extremely damaging, cycle of "binge and starve" eating. This cycle often begins when an individual attempts to restrict their food intake order to lose weight, but then "breaks" their diet and overeats due to feelings of deprivation and hunger.
Dr Graham McGregor, professor of cardiovascular medicine at St George's Hospital, London, says: "We did studies on medical students in which we saw that people who fasted would get so hungry that they'd then binge on the worst possible foods. It is a see-saw effect. You also get lots of salt one day and very little the next, which has a dramatic effect on the body. It is a totally unphysiological thing to do."
Despite the stresses that such extreme eating patterns place on the human body - overloading the digestive system, raising blood pressure and causing dehydration - Dr McGregor believes that this is now extremely widespread.
"Most women starve and binge to an extent," he says. "They want to lose weight, so they eat very little, then they get really hungry and when their boyfriend takes them out to dinner, they eat a huge meal."
While Dr Johnson, who is based in New Orleans, admits that extreme diets can trigger or exacerbate eating disorders, he denies that his new diet encourages this sort of unhealthy behaviour. He insists that the small amounts of food allowed on down days are enough to prevent dieters experiencing the extreme hunger that could lead to gorging on up days.
"I haven't seen anybody on this diet who goes to extremes and binges or starves," says Dr Johnson. "I don't recommend going without food completely, because if you starve all day then that can trigger a loss of control and you'll be non-stop eating." He believes that the diet actually regulates the appetite, meaning that if people have eaten lots one day, they will be less hungry the next.
Denney disagrees. "Eating lots one day and little the next doesn't teach people the importance of balance in their diet," she argues. "Young people in particular need to learn to regulate what they eat, and a day of gluttony followed by a day of starvation won't help them to do this."
Dr Johnson's book claims that the roller-coaster calorie consumption of alternate day eating is not only easy to follow, but also triggers physical effects that help followers to lose weight. While most low-calorie diets slow down the metabolism, reducing the rate at which the body burns calories and thus hindering weight loss, Dr Johnson insists that his diet works to speed up the metabolism, tricking the body into burning up more calories than before.
"There was a study at the Pennington Biomedical Research Institute where volunteers ate nothing at all every other day for three weeks. They lost 2 per cent of their body weight over that time, but their resting energy expenditure didn't change. The alternating days system prevented the metabolic rate from dropping."
The idea for the diet came about after Dr Johnson, who had struggled with his own weight, spotted a scientific study in the American Journal of Clinical Nutrition which suggested that mice that were fed only every other day experienced significant weight loss and other health benefits.
"When I read it, it struck me like a thunderbolt," says Dr Johnson. "It just made sense. Personally, I knew that I couldn't do 'not eating anything' on alternate days, but I could cope with consuming about 20 per cent of my normal daily intake."
In the clinical trials Dr Johnson conducted in 2004, he said that volunteers lost on average 8 per cent of their body weight over an 8-week period, and experienced other health benefits.
"I was sure that the diet had benefits other than losing weight, so I picked some asthma sufferers to take part in the trial," adds Dr Johnson. "They showed dramatic improvements in their peak flow (how fast you can blow air in and out of your lungs). There is a clear biological hypothesis for this - the very low calorie intake on the down day triggers an anti-inflammatory gene, which improves the asthma."
Johnson believes that his diet can also help to lower blood pressure and improve conditions such as arthritis, as well as reducing levels of potentially harmful free radicals in the bloodstream - claims that have already met with some scepticism.
"I'm unaware of any evidence that supports this hypothesis," insists Dr McGregor. "I mean, what happened to the Atkins? People who try diets like this might lose weight at first - because they are watching what they are eating - but they'll put it back on again."
While doctors may be right to question such a radical diet, Dr Johnson's plan does seem to have tapped into something. Internet message boards are heaving with glowing testimonials from thousands of people already subscribing to the schizophrenic eating patterns. Oddly, perhaps it is precisely because it is so extreme that Dr Johnson's "feast and famine" approach appeals to the dieters of 2008 - in a culture of size zeros and rising obesity levels, it doesn't seem all that crazy.
Day by day: the diet
I'm not desperate to lose weight, but with summer on the way, the thought of baring arms, legs or anything in between is enough to make me wish that the needle on the scales hovered a few lines lower. I decide to start on an "up" day, meaning that I can eat anything I want. Turns out, I want a lot of food, most of it fattening.
My usual breakfast of porridge or toast is eschewed in favour of a cinnamon roll and two pains au chocolat, sushi lunch swapped for a giant panini and crisps, and modest dinner replaced with an Indian banquet, followed by a box of chocolates. I could get used to this diet.
I wake up the next day nursing a "food hangover", complete with dry mouth, gurgling stomach and slightly sick feeling. If this continues, avoiding food should be a doddle.
Needless to say, it doesn't last. At 10.30am I can smell toast, and it's a damn sight more appealing then the strawberry meal-replacement shake Dr Johnson recommends I "sip throughout the day". By 4pm, I'm grumpy, tired, shaky, and more than a little hungry.
I'm allowed a meal in the evening, as long as it is less than 250 calories, and leaf through Dr Johnson's recipes in search of something edible. No such luck. I settle for a broccoli omelette, which wouldn't fill the gap in a hollow tooth. I sneak in a cracker with jam before bed, which sends me over my calorie limit. This is nowhere near as fun as yesterday.
The cycle continues for the rest of the week - I feel too full one day, and too hungry the next. When I finally step on the scales, I find I have lost 2lbs. I'm pleasantly surprised, but I won't be sticking with it. Dr Johnson is right about one thing - it doesn't feel like a diet. Shame it doesn't feel great either.
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