The ‘eat-too-much do-too-little’ hypothesis of obesity claims that weight gain is a result of laziness and greed on behalf of the afflicted. The theory suggests that by forcing calorie restriction and increasing physical activity weight loss will occur in obese individuals. However, obesity is a complex metabolic disorder which results from an inability to compartmentalise and utilise energy correctly. That exercise is beneficial to obesity is true, but not for the reason often stated. Studies show that exercise does not improve weight loss in subjects because it causes energy utilisation, as the calories oxidised during exercise are only a small fraction of the total daily energy expenditure. Instead, exercise can be used to treat obesity because it causes muscle gain, which improves resting metabolic rate. This is beneficial because the resting metabolic rate contributes by far the largest portion of energy expenditure in a 24 hour period.
Endurance exercise is not effective at increasing muscle mass because it is largely catabolic. In order to increase muscle mass, resistance training is necessary as it is an anabolic stimulus that result in the synthesis of new muscle tissue. Studies repeatedly show that resistance training is the most efficient way to improve body composition and resting metabolic rate, and has also been shown to be effective in children. For example, one group of researchers1 investigated the effects of 8 weeks of high intensity resistance training on adiposity and metabolic risk factors. Of the subjects, 18 % were obese and 51 % were overweight. The results showed that resistance training significantly reduced the waist circumference, fat mass, percent body fat and body mass index of the subjects compared to a control group. Resistance training also increased the upper and lower body strength of the children as would be expected.
These results therefore suggest that resistance training is effective at improving the body composition of children. Interestingly, the researchers reported that the improvement in waist circumference was most significant in those children with the greatest initial strength as well as those with the largest relative and absolute strength gains during the study. This suggest that improving strength should be a goal of any individual wishing to improve body composition. These results are likely not surprising to any individual that has undertaken serious weight lifting, power lifting, body building or other form of resistance training. Such athletes, particularly body builders, tend to have low a percentage body fat despite eating almost continuously and doing little endurance exercise. The continual eating is necessary to provide energy for the resting metabolic rate, that is often significantly higher than normal in such individuals.
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