Alternate Day Fasting: Well-Researched, Proven to Be Effective. So Why Don't You Use It? Plus: Simple Alternate Day Fasting Blueprints to Get You Beach Ready in 2014

Alternate, better than intermittent fasting?

I know the hardcore "Martin Berkhan Intermittent Fasters" are laughin', whenever they hear about alternate day fasting. What I don't know, though, if whether they will still be laughing, after they read this article, which is a brief summary of the latest research on a way of "dieting" with immediate beneficial effects on body weight, body composition, glucose and fatty acid metabolism that is.

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.

To make the most of your ADF regimen, you better have your meal for dinner - not for lunch (Hoddy. 2014)

Why does alternative day fasting work? The reason you are losing weight is that you will automatically cut calories. Previous research shows that you are not going to compensate for the 60% reduction in energy intake during the fast (I am using a baseline of 2,400 kcal per day, here) - not at all after one day (Levitsky. 2010) and only to a very limited extend on longer alternate-day fasting regimen. If we assume that for most individuals the "rebound" is <20%, this would imply that you'll be consuming 40% less energy than usual on a regular "every-other-day fast" against background it's no wonder that this way of dieting this will shed ~1kg per week.

You got to be cautious, though, if your alternate day fasting cuts your energy intake to levels that mirror a starvation diet (40% or more of below your requirements), you better keep the ADF phases short, like in four weeks to avoid metabolic shutdown (you will learn more about alternatives later in this article).

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)

I mean, we are lucky to have data on the overall beneficial effects and the equivalence to isocaloric calorie reductions (in terms of weight loss and health benefits, cf. Harvie. 2011), a metabolic ward study that compares the effects of three different alternate-day fasting regimen over a time period of several months (which is the human equivalent of 4 mice-weeks), on the other hand, is something you are probably going to see only in your wildest dreams.

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".

As exemplified in Figure 2, you could just follow your regular square 3 meals (30g+ high-quality protein per meal) plan on DAY 1, skip breakfast and launch on DAY 2 and have a huge bowl of veggies, two slices of salmon and two to three spoons of olive oil for dinner and an optional protein shake as a dessert or in place of "bedtime candy".

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)

On the not obesity / metabolic syndrome related side of things, we can register

• 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)

And, as I've hinted at in the 2nd blue box, even the athletic almost, or already ripped SuppVersity reader could benefit - with only two fasting days and a consistently high protein intake probably even on a bulk.

You are scared that skipping breakfast would be bad for you? Well, in that case, you should read my previous article on the myths surrounding the "most important meal of the day".

So should be all be alternate day fasting? I would not go so far as to say that you have to "fast alternately" for the rest of your lives. What I do suggest, though, is that you remember that ADF is a practical and effective strategy in your toolbox.

Based on my personal experience, it is significantly more convenient and a lot easier to adhere to than classic "intermittent fasting". Its efficacy is beyond doubt - even from a scientific perspective. And as long as you modify / adapt the number of fasting days, it can (probably) be done infinitely - as long as you don't end up at a weekly caloric deficit of >40%, probably indefinitely and could eventually even prolong your life (Johnson. 2006)

References:

• 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.