Calorie Restriction vs. Exercise for Optimal Body Composition? Exercise Preserves Muscle Tissue and Prevents Metabolic Downregulation.

Those of you who listened to my comments on set points and reasonable weight loss on Super Human Radio, will already know that - other than Gary Taubes, for example - I am a huge advocate of exercise, when it comes to weight loss, -maintenance and overall improvements in body composition. Data from a recently published study (Soare. 2011), despite being evaluated from an anti-aging perspective, confirms the adequacy of approaching your body composition goals, by dietary modifications and exercise induced increases in energy expenditure, instead of just "eating less calories".

In their study, Soare et al compared 24 subjects who had been on a calorically restricted diet (CR, 1769±348 kcal/d) for an average of 6 years to 24 age- and sex-matched sedentary individuals (control, WD, 2302±668 kcal/d) and 24 body fat-matched exercise-trained (EX, 2798±760 kcal/d) volunteers, who were eating Western diets.

Figure 1: Total body weight, lean mass & fat mass in sendentary control, calorie restricted (CR) and exercise (EX) group. (Data adapted from Soare. 2011)

Although the researchers found that both, "the CR and EX groups were significantly leaner than the control (WD) group" both the greater amount of lean body mass (cf. figure 1) as well as their finding that...

Mean 24-hour, day-time and night-time core body temperatures were all significantly lower in the CR group than in the WD and EX groups (P≤0.01).

...underline the futility of every effort to achieve improved body composition, i.e, to maximize muscle (lean mass), while shedding as much body fat, as possible via (even moderate) caloric restriction.

Two other things are noteworthy, as well. Firstly, the reduction in body temperature, which is indicative of a downregulation of the metabolic rate, may be favorable for a longer, but that does not equate into more livable life. And secondly, the "Taubes-Hypothesis" that exercise is "useless", because "it makes you hungry" (the subjects in the EX group in fact consumed more calories) and you would compensate by eating more, anyway, would be relevant, only, if in fact "a calorie was a calorie" and "only calories" counted; the superior body composition of the exercise group, on the other hand, speaks for itself and does suggest that even Garry himself may benefit from one or another training session in the gym ;-)

Edit: As I hear in an anonymous comment Taubes is supposed to do resistance training. When he was talking to doctor Oz, he did however propose the hypothesis I refer to above and this really bothered me.

Calcium + Vitamin D for Breakfast Increase Dietarily Induced Thermogenesis and Fatty Acid Oxidation

Ever since the first studies suggested beneficial effects of dairy on weight loss, there have been a lot of trials that investigated the role of (supplemental) calcium in these contexts (mostly with discouraging results). A very recent study by Wendy and Soares (Wendy. 2011) took a very similar approach, but added vitamin D to the equation.

In their study, the scientists fed their 11 subjects (aged (mean ± SEM) 54 ± 1.2 y and BMI 31 ± 2.4 kg/m) a meal that was either high (HCT) or low (LCT) in vitamin D and calcium and measured diet induced thermogenesis (DIT), fat oxidation rates (FOR), serum leptin, subjective feelings of hunger/satiety hourly over a period of 8 hours. The results were far from earth-shattering; they could however solve the mystery of why most people find it easier to lose weight on a diet that is generally rich in dairy and calcium + vitamin D rich foods:

HCT resulted in lesser suppression of ΔFOR (p=0.02) and a significantly greater DIT (p=0.01). Further, the buffet to dinner interval was prolonged (p=0. 083) and reported 24h energy intake following this trial was significantly reduced (p=0.017). ∆leptin following HCT but not LCT was negatively related to 24 h fat intake (r = - 0.81, p=0.016).

So, the underlying mechanism is actually threefold and much different from the commonly heard hypothesis that dietary caclium would "bind fat in the intestine" and thus reduce caloric intake:

1. greater postprandial fat oxidation
2. significantly greater thermogenesis
3. beneficial effect on leptin and thus decrease in hunger

What else would you want? If there was not the issue with lactose intolerance, eating as much dairy as possible could actually become a general recommendation for everyone who intends to lose weight and/or improve body composition

Overweight Boys More at Risk of Obesity Related Health Problems than Girls

In a recent study from Egypt, Hassan et.al. took anthropometric measures of adiposity from 150 pupils between the ages of 7 to 18. Along with data on body composition and serum total lipids profiles the scientists intended to find correlation between obesity and adverse health effects at younger age. The results are interesting in that no correlation was found between lipid profile and body composition in the adolescent group (12-18 years). On the other hand, in the younger children , ...

For young age [7-11 years], triglycerides and HDL-C are correlated to most of the body composition and anthropometric parameters in boys and not in girls.

The scientists speculate on whether the different fat distribution pattern in young boys (centrally dominant) could be one of the underlying reasons for this observation. Be that as it may, I consider this another good reason to encourage boys (and girls, alike) to act out their natural desire to move and exercise before they  become PlayStation cambling couch potatoes.