Appearing today in the Sophian, as a Letter to the Editor:

Fat and fit?

Rachel Johnson’s Nov. 18th opinions piece on the burgeoning “Fat Studies” movement brought up some good points about the challenges of supporting a group marginalized not because of race, religion or ethnicity, but because of size.

As Johnson wrote, the movement strives to eliminate some of the stigma and discrimination that often come with being overweight or obese, as the 66% of Americans that fall into these categories can attest to. Furthermore, as Johnson noted, the field aims to promote the understanding that obesity is not simply the product of indolence and a lack of willpower, but rather a factor of “a range of social, economic and genetic factors.”

While Johnson supports the aim of Fat Studies to rectify the historic mistreatment of those Americans “of size,” she is critical of the notion attributed to the movement that the health community is biased and favors an alarmist agenda with regard to preventing and addressing obesity. While it is certainly legitimate to critique the nascent Fat Studies movement, I believe that Johnson’s criticism does not acknowledge the growing scientific understanding that weight is not necessarily correlated with health or lack thereof.

It is my opinion that public health agencies like the NIH, CDC and others do in fact approach the complex issue of obesity with an alarmist zeal, and perhaps some of that alarmism is warranted. After all, the NIH, CDC and so on have as a goal a reduction of risk to the general public, but their alarmism has done little to curb the growing numbers of Americans with a Body Mass Index of 25 or higher i.e. who are overweight.

What then is the basis of my disagreement with Johnson and others who see Fat Studies as promoting the faulty notion that being overweight and obese does not in fact put a person on a direct path to Type 2 Diabetes and other markers of poor health?

I believe that there is in fact sufficient evidence to suggest that overweight and obesity is not in and of itself deadly/a burden to society/etc. etc., and that some of the deleterious health consequences associated with obesity can in fact be attributed to the stigma that society attaches to carrying “excess” weight.

One avenue of research that has yielded such evidence has focused on the so-called “fit and fat” debate. That is, is it possible to be both “fat” (overweight or even obese) and physically fit? Moreover, is it more important to be thin, or to be fit?

University of South Carolina Professor of exercise physiology, epidemiology and biostatistics Steven Blair has made his life’s work to examine this very issue. Blair is himself an overweight and active individual who, after running almost every day for more than 30 years, is “still short, fat, and bald.” Although his daily activity has not resulted in weight loss, Blair maintains that he is in “much better shape than I’d be if I didn’t run.”

One notable study Blair conducted in 2007 investigated the relationship between fitness, weight and mortality. Fitness was found to be strong predictor of longevity in the participants, all adults 60 and older, while obesity was found to have little influence on risk of death. Especially in older people, Blair reported, obesity is “not as important a determinant of mortality as it is in younger people.”

Synthesizing the study’s results, age, low fitness levels and having multiple risk factors for heart and vascular disease were independently associated with death risk, and better fitness was associated with a lowered risk of diabetes, high cholesterol and high blood pressure.

As for fitness, death rates for those with the highest levels thereof were less than half that of the physically “unfit.” Being overweight and obese, however, was not an independent predictor of death, and among the physically fit, death risk was similar for normal weight, overweight and obese people. Blair also specified that 46% of study participants with a BMI of 35 or higher (“extremely obese”) did not fall into the lowest two tiers of fitness level.

The take-away message? Fat and fit can coexist, and fit is more protective than thin.

Blair is of course not the only researcher to examine the subject. A 2009 systemic review of the literature on the interaction of physical activity, fitness and “fatness” concluded that “the risk for all-cause and cardiovascular mortality was lower in individuals with high BMI and good aerobic fitness, compared with individuals with normal BMI and poor fitness.” These results did not apply to the very obese (BMI greater than 35), for whom risk of Type 2 diabetes and cardiovascular incidents was greater. In a similar vein, individuals who are underweight i.e. on the other extreme of weight, have been found to have a greater risk of mortality.

My point in highlighting this research is not to discount the evidence that a greater BMI may be associated with greater health risk, but rather to suggest that the relationship between weight and health is by no means a simple and straightforward one, and that I believe is where Fat Studies can play a crucial role. By challenging the “x leads to y” hypothesis, Fat Studies can help remind the public that measuring and predicting health is never a simple matter.

Advertisements