Intermittent fasting has gained popularity recently. What are your thoughts? Panacea or fad?
I think the popularity of intermittent fasting (IF) is, for the most part, a good vindication of science. Academics have known for a while now that research has not supported the lore of frequent, small meals to stoke the metabolism better than the equivalent in larger, fewer meals. Furthermore, research has not supported the idea that small, frequent meals are necessary for preserving muscle mass. The evidence as a whole has not indicated any threat to muscle preservation during dieting when meal frequency is reduced – either daily or intermittently through the week. In fact, some studies have shown superior lean mass retention with IF during hypocaloric conditions. However, this could have been due to measurement error inherent with bioelectrical impedance analysis. It should also be noted that the IF research thus far has not involved structured exercise protocols.
At the same time that IF has vindicated science, it also created its own over-zealous following who preaches its universal necessity for optimizing body composition and health. Viewed more objectively, IF presents an effective option for those who prefer the convenience and luxury of larger meals – not to mention, less preparation & transportation of meals through the day. Any special or superior metabolic effects of IF compared to conventional meal patterns are speculative at this point. While IF has consistently shined in the department of lean mass retention while dieting, its comparison to conventional meal frequency on gains in muscular strength & hypertrophy is uncharted ground, at least in formal research. There are plenty of hypotheses flying around this area, but nothing demonstrated under controlled conditions. For the time being, meal frequency for optimal size & strength gain remains mysterious. This mystery is likely to begin unfolding with short-term data that one camp will excitedly embrace. If history means anything, the acute data will be followed by long-term data that shakes the confidence in former beliefs. Either way it goes, I’ve got my popcorn ready.
On a final note, I’ve seen the greatest client success come from letting individual preference dictate meal frequency. Some people do great on small frequent meals, others do great on the opposite (and all points in between). The theoretical advantages of any given dietary approach go straight out the window if it’s at odds with someone’s personal preference & adherence capability.