Fitness, Fatness and Health

Regular readers of these postings are well aware of the notion that BMI alone is but a poor indicator of personal health.

Many studies now point to the fact that good health is possible over a wide range of body shapes and sizes and in many cases may depend more on fitness, family history and other risk factors such as smoking rather than on the numbers on your scale – this at least appears true if we define health as longevity but may not apply to all weight-related health conditions.

This appears to be the essence of a systematic review of the literature on physical activity, fitness and fatness and their relationship to mortality, morbidity and disease risk factors, by Mikael Fogelholm from the The Academy of Finland, Helsinki, just published in OBESITY REVIEWS.

The analysis of 36 eligible publications confirms that the risk for all-cause and cardiovascular mortality is lower in individuals with high BMI and good aerobic fitness, compared with individuals with normal BMI and poor fitness.

In contrast, individuals with high BMI, even with high physical activity, are at greater risk for type 2 diabetes and other cardiovascular risk factors, than individuals with normal BMI and low physical activity.

This means that although physical activity may not prevent overweight and obese people from getting diabetes or other cardiovascular risk factors, being physically fitter still appears to protect them from dying of these complications.

As one of the major arguments for treating diabetes and other cardiovascular risk factors is to prevent premature deaths, I cannot help but wonder if the relative benefits of these treatments may be greater in normal weight sedentary individuals than in physically active people with higher BMIs.

Not sure we can answer this question with the current analysis or any other data that I am aware of.

For now, I will of course continue recommending “optimal” management of diabetes and cardiovascular risk factors to all my patients, irrespective of their fitness levels.

Edmonton, Alberta