Monday, December 24, 2012

"Mini-Fast With Exercise" a la Intermittent Fasting Can Help Minimize the "Damage" During the Holiday Season

I wonder if it is coincidence that the modern Santa is an obese advertisement character invented by some marketing genius working for Coca Cola?
Those of you who have been reading the intermittent thoughts on intermittent fasting (click here and start with the links at the bottom, if you haven't) will remember that the actual number of studies on intermittent fasting, as it is interpreted by most people on the Internet is actually quite scarce. Aside from the Ramadan studies, you mostly see very long fasting periods or other oddities that decrease the significance of the studies. That said, I did hit onto an older study that has been published in Medical Hypothesis in 2009, already. A study with a daily 12-14h "mini-fast" + low intensity aerobic exercise 5x a week and a study the results of which point to the usefulness and practical value of skipping a meal - especially in a time where you give in to nutritional temptations way too easily, anyhow - the holiday season!

Fast, walk, eat and stay lean during the holiday season and afterwards

Especially for those of you who are having some weight issues anyway, the profound body fat loss, the subjects in the Bahadori study which was based on a 7 step program comprising
    * Better than monitoring total fat and GI would be to monitor your N-6 intake, emphasize mono-saturated fatty acids and eyeball the total glycemic load (the latter means potatoes are ok, but cookies are a "better stick to one" item ;-)
  • a mini-fast with exercise (12–14 h) fast during every 24 h + prolonged, moderate-intensity aerobic exercise (e.g. 40-45 minutes of brisk walking) Meals are not
  • no caloric restrictions, but a focus on low fat, low GI meals*
  • an increased consumption in calorie-free beverages during the fast
I know that sounds stupid and 100% mainstream, but if you take a look at the data in figure 1 you will notice that it worked like a charm... well, at least for the 10 overweight men and 17 women who followed this protocol for 12 months.
Figure 1: Body weight and composition, waist and insulin levels from the beginning to the end of the 12 week non-calorically restricted 10-14 hour fast with light aerobic exercise; the asterisk (*) behind body fat (%) and insulin signifies that these values are plotted on the 2nd-ary axes (Bahadori. 2009).
Personally, I believe that one, if not the reason that this protocol worked so well were it's feasibility and flexibility, as well as being allowed to eat to satiety, when the subjects were not fasting. The 27 subjects who participated in the study were also free to chose whether they wanted to skip breakfast or dinner and switch from one to the other strategy on a daily basis to adapt their diet to their working hours and other obligations:
Coffee and teas like green, black oolong and pu-erh are your friends not just during the mini-fasts (read more).
"If participants choose to exercise in the morning, they skip breakfast and do not eat until noon. If they choose to exercise at noon, they skip lunch. If they choose to exercise in the evening, they eat an early light dinner, and then wait at least two hours to exercise (so that fasting insulin levels are restored); no food is consumed between the exercise and bedtime. (A variant of this latter strategy is to eat no dinner at all; several volunteers in the study described below adopted this approach on their own initiative.) To optimize the flexibility of this regimen, participants are allowed to switch the time of their exercise session from day to day." (Bahadori. 2009)
For your personal Christmas fast this could mean you skip breakfast tomorrow (which should not be a problem with the large Christmas dinner in your tummy), go out for a long brisk walk, have a light dinner, like a mixed salad with some cheese and chicken breast, and thus prepare yourself for the next family feast on Christmas day. If you are brunching on the day after Christmas, not a problem, you just sleep out, go for light 30min jog, shower and head over to the brunch. Eat as much as you like, and either skip dinner later or breakfast the day after.

If you are not into coffee and tea, ginger ale is another fasting friendly weight loss drink (read more).
Bottom line: To keep the damage at bay this the "mini-feast + exercise" protocol is probably feasible for anyone. It's easy, it will allow you to take part in all the Christmas festivities and won't have you sit there like an orthorexic leopard who cannot change his spots .

Whether this is a strategy worth following for longer depends on where you are at and where you want to go. If you want to look like a fitness model, it's unlikely to be sufficient to reach your goal. You will, for example, have to tweak that regimen to (a) incorporate strength training or add it in later in the day, (b) think about using a couple of supplements, such as BCAAs, caffeine and green tea during the fast and (c) eyeball the quality of the foods you eat with convenience, fast and junk-food being the exceptions to the rule of eating self-prepared whole food meals.

There are however certain downsides to protocols like this, a potential increase in adipogenesis (22% vs. 12% fat gain) and decreased lean gains (50% vs. 72%), as they were observed in a rodent study by Verbaeyes et al. (see "Eating by The Clock Could Make You Fat") with unrestricted caloric intake within the 6h feeding window, would be an example and evidence that whenever you are effectively trying to gain weight you are probably better off spreading your food intake more evenly across the day. Alternatively, you can enlarge the feeding window to 10h to maximize lean gains without the negative side effects of force-feeding yourself with 2x1,500kcal meals only twice a day or grazing continuously for 6h to meet your caloric demands.

But hey, Christmas is almost there, and there is still enough time to think about dieting and bulking after the festivities. On that note, I wish all of you a happy Christmas, a nice time with your families, friends! Regardless if you fast or not ;-)

  • Bahadori B, McCarty MF, Barroso-Aranda J, Gustin JC, Contreras F. A "mini-fast with exercise" protocol for fat loss. Med Hypotheses. 2009 Oct;73(4):619-22.