©2018 by Smith Health Optimization LLC


"Minimizing Adaptive Thermogenesis and Deactivating Obesity Rebound": The MATADOR Study

November 5, 2017


November 5th 2017, Sunday. 16 weeks and 9 days out from my next bikini competition.

Wt: 158.0 lb, 31.5% body fat (0.2% drop), BMR 1971.0 kcal

Current daily calorie deficit: 87.7% of BMR (1,730 kcal) (12.3% reduction from BMR baseline)

Cardio: HIIT X 3 30 second bursts, the rest steady state on elliptical, total of 30 minutes, fasted (300 kcal) for a total of 541 kcal deficit for today (not including weight training later today)


              Drinking my morning coffee after meal #1, post fasted am cardio, I again come across Dr. Layne Norton’s YouTube channel. In this episode, (https://www.youtube.com/watch?v=6gQCqxnchR4) he covers a recent study by Byrne et al., “Intermittent energy restriction improves weight loss efficiency in obese men: the MATADOR study”. I also, of course, read the original article, and it’s solid (https://www.nature.com/ijo/journal/vaop/ncurrent/pdf/ijo2017206a.pdf). This falls right in with a lot of the information I have been hearing out there regarding metabolic adaptation and how to make weight loss more sustainable after the diet is over. We are in such a downward spiral as a country when it comes to obesity and fad dieting. People are working harder than ever to lose the weight. Maybe it’s time we work smarter. It has been shown repeatedly the body has a complex hormone system that adapts quite quickly to changes from baseline including energy intake (calories). A second layer to that is, as the body composition changes (weight loss), again the body seeks to regain homeostasis, and so lowers the resting metabolic rate. To counter these two adaptations and keep the body moving in the desired direction (body fat loss while minimizing lean muscle loss), the researchers of this study employed a 2 week on energy restriction of 33% calorie reduction from basal metabolic rate (BMR) followed by a 2 week return to maintenance calorie intake equal to BMR. (Note: the authors of this study used a more complex calculation of BMR, aka resting metabolic rate, which they called resting energy expenditure which is beyond the usual means of the average person to utilize in day to day life. The point is to pick a reliable tool that is easy to use and take measurements under the same conditions on a consistent basis and track changes over time). The researchers compared the results of these intermittent dieters with a control group of consistent dieters. Both groups had a total calorie restriction of 33% for 16 weeks (the intermittent group took 30 weeks to reach the end due to the 2 weeks on restriction followed by alternating 2 weeks on maintenance calorie intake (= to BMR) – which was recalculated prior to each 2-week maintence period as the BMR changed with weight loss). The intermittent group not only lost more body fat, they also maintained a higher BMR for their total body weight which may be attributed to better body composition (more lean muscle mass to body fat ratio) and less adverse hormonal metabolic adaptations than the continuous dieters. Further, in a 6-month follow up, the intermittent dieters remained leaner than they had before the study, while the control group had regained weight to their previous levels or more.

              The art and science of body composition manipulation is complex and yet also so simple. It is still a matter of energy in and energy out. But the metabolic adaptations that dictate this process are complex and must be fully understood to be successfully manipulated to reach the ultimate goal of ideal body composition for life. Using such a technique as intermittent calorie restriction periods with periods of maintenance calorie intake works with the body’s system, not against it, to achieve sustainable body fat loss over the long term.

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