The Obesity Myth: Health at Every Size

By Isobel Whitcomb ‘17
Environmental Columnist

Many people are already familiar with the way the mass media perpetuates the social stigma against being fat. Every day we are bombarded with images of often unrealistically thin women and men. We see them on magazine covers as we wait in the check-out lane at grocery stores and posted on social media sites, while similar photos of fat people are flagged as “inappropriate” and taken down. However, most people are not aware of the way science and the medical establishment are complicit in this moral panic. After all, if there is one thing Americans are taught about health from an early age, it’s that being fat is unhealthy. So what happens when we begin to question that key tenet of the medical establishment?

In 2013, Doctor Katherine M. Flegal published a scientific review in the prestigious Journal of the American Medical Association investigating the link between mortality and being overweight and obese, using standard categories of body mass index (BMI). The review compiled all 143 recently published studies that published results on BMI and mortality, and found that while higher grades of obesity (BMI>35) were associated with higher mortality, being overweight or in a lower obese range (a BMI of 25-35) was actually associated with lower mortality risk than "healthy weight" participants.

This study is not suggesting that readers panic about the link between their BMI and potential higher risk of mortality. However, this study should cause the scientific and medical establishment as well as the American public to pause and question what we have been taught about our weight and health. After all, there are a variety of explanations for correlation between weight and health. In one example, a person in a lower income area of LA who is exposed to higher levels of environmental toxins might have a higher risk of obesity and poorer health than a person in a upper class area of the city. In this scenario, obesity is not necessarily causing poor health. Rather, the same set of variables (dubbed "confounding factors") are causing both obesity and poor health. Other possible confounding factors, could include socioeconomic status, dieting tendencies, tendency to weight cycle (commonly called “yo-yo dieting), and mental health. 

The confounding factors I mentioned above were all used in attempts to discredit Flegal’s 2013 review. But these critics all forgot one problem with their argument- that if confounding factors influenced the results of Flegal’s study, then they are also equally likely to create the potentially false perception that being overweight is unhealthy.

The truth is that the association with being overweight or obese and health is shady at best. Since Flegal’s article was published three years ago, dozens of studies and reviews have reiterated that fact. One such study, published in December of 2015, separated participants into categories of “metabolically healthy” and “metabolically unhealthy” as well as standard BMI categories and compared the likelihood of participants having a heart attack.

The results of this study were similar to those of Flegal. It found no difference between the likelihood of heart attacks in metabolically healthy, “normal weight” and “overweight” individuals, and found that metabolically unhealthy “normal weight” participants were actually more likely to experience a cardiovascular event than metabolically unhealthy “overweight” participants.

Although this study found that obese patients were significantly more likely to suffer a heart attack, this result may have been due to a flaw in the researcher's methods, which exhibited some of the assumptions and problems typical of research on weight and health. Unlike Flegal, the study placed all obese people into one category- a major problem because, as Flegal found, there can be big differences between a person with a BMI of 30 and another with a BMI of 40. In addition, unlike Flegal’s study, it only investigated heart attacks, rather than all-causes of death. Such an approach makes it difficult to assess whether socioeconomic status or dieting tendencies associated with certain BMI groups have an effect on overall mortality.

According to Paul Campos, the author of The Obesity Myth, scientific complicity in the war on obesity is a classic symptom of a moral panic. “As public concern about the damage being done to the fabric of society... increases, increasingly intense demands are made on public officials to “do something” about the crisis.” While “it’s good to encourage people of all sizes to be active and avoiding eating disordered behavior (like dieting),” Campos argues that “this isn’t because lifestyle changes will make fat people thin people. They won’t.”

The take away message from these reviews is this: there is too little hard medical evidence on weight and health to make any distinctions between categories. This lack of a conclusion is in itself revolutionary. It’s a sign that we need to question how deeply ingrained our assumption is of the link between fatness and health.