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Feature Articles: Food, Fitness and Weight Control

Is Obesity a Disease?

Stephen D. Ball, Ph.D., Nutritional Sciences, College of Human Environmental Sciences, University of Missouri-Columbia


There is little question that Americans are getting fatter despite one third of all adults trying to lose weight at any given time. A staggering 30 billion dollars are being spent annually on weight loss products and promotions, yet as a nation we are gaining weight at an unprecedented rate. Some statistics report that approximately half of all adults in this country can be considered overweight and nearly one third can be classified as obese. Childhood obesity has also doubled in the last 20 years. These epidemic proportions have forced the medical community, fitness and health professionals, dieticians, and government agencies to "wage a war on obesity." Former President Clinton was even encouraged to declare obesity a national health crisis and in 1998 the World Health Organization officially declared obesity a disease.

Currently there is a heated debate within the fitness and health care professions over the classification of obesity as a disease. There is little question that obesity is associated with a variety of negative health risks such as high blood pressure, hyperinsulinemia, increased cholesterol levels, diabetes, and even certain cancers. However, it is still unclear if obesity is the cause of these risk factors. I believe it is too premature to declare obesity a disease, and that by doing so, it will only make the situation worse.

Why? First, is obesity itself generating the associated health risks? Perhaps obesity is only a marker for poor health but is not the direct cause. Research has not been able to definitively conclude obesity to be the causal factor of its associated negative health outcomes. Research has shown that diet and activity levels, contributors to obesity, are also related to cardiovascular disease, cancer, and strokes despite body weight. In addition, there is strong evidence that overweight, but active individuals, are at a lower risk for cardiovascular disease than thinner counterparts that are not active. In a series of landmark studies at the Cooper Institute, renowned epidemiologist Steven Blair (1996) found that the best predictor of mortality was cardiovascular fitness independent of body weight, Body Mass Index (BMI), or % body fat. In other words, an obese person by BMI or % body fat standards that has good cardiovascular fitness is at a significantly reduced risk of all causes of mortality compared to a normal weighted individual that has low cardiovascular fitness. In other words, you can be overweight, or even obese, as long as you have good cardiovascular fitness. It seems that being overweight or obese becomes less of a factor when activity and diet are controlled for, something that most obesity researchers have not considered. More research must be done in order to distinguish the contribution of each before we can clearly say that obesity itself is the culprit.

By declaring obesity a disease many unhealthy strategies for weight loss (stomach stapling, liposuction, diet pills, body wraps, herbal remedies, etc.) for weight loss might become warranted. Doctors could justifiably use these treatments and feel confident that they are improving the client's health simply by decreasing his or her weight. Pharmaceutical companies would be able to market their quick fix pills and quacks could promote radical diets that promote fast weight loss. It must be emphasized that the effect of these treatments would only be temporary since they don't address long term behavior change such as lifetime physical activity and improved dietary habits. In addition, even if weight loss is achieved and maintained there is no guarantee that it will be accompanied with health benefits.

Finally, calling obesity a disease will likely promote our nation's preoccupation with weight loss. This would take away from focusing more on the processes of healthy living and would undermine the entire purpose of health promotion. The newly warranted unhealthy weight loss practices would ultimately decrease the public's overall health and would actually drive health care costs up. We must focus not on the product (weight) but on the process (healthy behaviors). We shouldn't be waging a war against obesity but rather a war against inactivity and poor lifestyle choices. Perhaps it would be better to declare inactivity a disease. Maybe this would finally divert attention away from the bathroom scale and help us to start focusing more of our efforts on increasing activity and fitness levels.


Key Reference: Lee, C.D., Blair, S.N., Jackson, A.S. (1999). Cardiorespiratory fitness, body composition, and all-cause and cardiovascular disease mortality in men. American Journal of Clinical Nutrition, 69:3, 373-380.






Last update: Tuesday, May 05, 2009






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