|Alternate, better than intermittent fasting?|
For 99% of the population it is also much more feasible than the classic "everyday intermittent fast" that was popularized by Markin Berkhan's Lean Gains protocol, which has - probably due to lifestyle-incompatibilities and the overall inconvenience - already been abandoned by a lot of its initial fans.
So, is alternate day fasting (ADF) the "better" intermittent fasting?
Although I guess, I don't have to repeat the basics, it may be useful to initially get this straight: When I am talking about "intermittent fasting" as in "alternate day fasting", this implies that you eat absolutely normal (to your usual satiety level) on day 1, and consume max. 800kcal (the fast) on day 2.
Unfortunately, the number of currently available human trials is still limited - not with respect to the presence of significant health improvements and weight loss, don't worry. Rather with respect to the underlying mechanisms and more intricate effects such as those K.A. Varaday et al. observed in their 2007 rodent study (Varady. 2007).
|Figure 1: Fat cell size in inguinal and epididymal fat (visceral fat) after 4 weeks of alternate-day fasting (Varady. 2007)|
In my humble opinion, it's yet very unlikely that "not eating" will be more effective than cutting back by 50% in humans, when it does not provide additional benefits in mice. Moreover, cutting back by 50-60% leaves more than enough room to turn the whole spiel into something like an alternate day protein modified fast. Practically speaking this could look like this:
|Figure 2: You can turn your alternate day fasting regimen into an "alternate day protein fast".|
The athlete's approach to every other day fasting would obviously differ from the one above. For someone with a high to very high activity level and an already presentable physique, two "fasting days" per week would be more than enough. In view of the fact that fasting on Monday and Friday, for example, is hardly going to induce any significant muscle catabolic effect, the "two-days-a-week alternate day protein-modified fast" could even be used to limit fat gains and, more importantly, ill health effects on a bulk.Especially for those of you who are still a few kilograms away from their bikini or speedo beach physique, alternate fasting has a whole host of advantages over "classic" friss die Hälfte (german, "eat only half of it") diets and the previously mentioned intermittent fasting:
|Figures 3 & 4: Reductions in blood lipids in obese subjects on a 4 week controlled + 4-week free-living alternate day fast (Varady. 2009b); Changes in adipose tissue visceral-to-subcutaneous fat ratio (bottom, Varady. 2009b)|
- easy to do + very high adherence rates compared to classic and - in the long run - intermediate fasting
- significant improvements in markers of cardiovascular health (Bhutani. 2010; Varady. 2009a & 2001)
- minimizes the ratio of visceral to subcutaneous fat (i.e. bad vs. good body fat; cf. Varady. 2009b)
- almost identical effects w/ high or low carbohydrate content (Klempel. 2013: -7% waist circumference, -5% body fat)
- beneficial effects on the clinical markers and general inflammation in asthma patients (Johnson. 2007)
- remaining 100% socially compatible on the non-fasting days (no "I am sorry, but my feeding window isn't open, yet)
- Bhutani, Surabhi, et al. "Improvements in Coronary Heart Disease Risk Indicators by Alternate‐Day Fasting Involve Adipose Tissue Modulations." Obesity 18.11 (2010): 2152-2159.
- Harvie, Michelle N., et al. "The effects of intermittent or continuous energy restriction on weight loss and metabolic disease risk markers: a randomized trial in young overweight women." International journal of obesity 35.5 (2011): 714-727.
- Hoddy, Kristin, et al. "Meal timing during alternate day fasting: effects on body weight and coronary heart disease risk in obese adults (47.5)." The FASEB Journal 28.1 Supplement (2014): 47-5.
- Johnson, James B., Donald R. Laub, and Sujit John. "The effect on health of alternate day calorie restriction: eating less and more than needed on alternate days prolongs life." Medical hypotheses 67.2 (2006): 209-211.
- Johnson, James B., et al. "Alternate day calorie restriction improves clinical findings and reduces markers of oxidative stress and inflammation in overweight adults with moderate asthma." Free Radical Biology and Medicine 42.5 (2007): 665-674.
- Klempel, Monica C., Cynthia M. Kroeger, and Krista A. Varady. "Alternate day fasting (ADF) with a high-fat diet produces similar weight loss and cardio-protection as ADF with a low-fat diet." Metabolism 62.1 (2013): 137-143.
- Levitsky, David A., and Lisa DeRosimo. "One day of food restriction does not result in an increase in subsequent daily food intake in humans." Physiology & behavior 99.4 (2010): 495-499.
- Varady, K. A., et al. "Effects of modified alternate-day fasting regimens on adipocyte size, triglyceride metabolism, and plasma adiponectin levels in mice." Journal of lipid research 48.10 (2007): 2212-2219.
- Varady, Krista A., et al. "Short-term modified alternate-day fasting: a novel dietary strategy for weight loss and cardioprotection in obese adults." The American journal of clinical nutrition 90.5 (2009a): 1138-1143.
- Varady, Krista A., Carolyn S. Hudak, and Marc K. Hellerstein. "Modified alternate-day fasting and cardioprotection: relation to adipose tissue dynamics and dietary fat intake." Metabolism 58.6 (2009b): 803-811.
- Varady, Krista A., et al. "Improvements in LDL particle size and distribution by short-term alternate day modified fasting in obese adults." British journal of nutrition 105.04 (2011): 580-583.