Obesity Arguments ad Absurdum

Obesity arguments over the health risks of excess weight were taken to a new level of absurdity with two publications in the last 24 hours. The first was an excellent study published yesterday in the Journal of the American Medical Association, documenting a survival benefit for overweight people. The second was a dogmatic editorial in the New York Times by Paul Campos using this study to advance the cause he’s been selling for some time in his book, The Obesity Myth.

Campos uses a classic rhetorical approach, reductio ad absurdum, to make the case that the health risk of obesity is a myth by claiming that the only alternative is a one size-fits-all standard for healthy weight. His argument is an unfortunate reaction to the very real, pervasive, and malignant weight bias that causes profound harm to millions of people.

People with obesity encounter discrimination and hateful treatment from an early age at school, at work, in healthcare, in social situations, and even in their own families. Research also shows that increasing bias and discrimination against people with obesity comes, at least in part, from a mistaken assumption that stigma and shame will motivate people to lose weight and improve their health. But in fact, the opposite is true. Stigma and shame lead to social isolation and unhealthy eating behaviors that make the problem worse. And it leads people to avoid necessary medical care.

Campos is doing nothing to solve this problem. In fact, he’s offering up another rationalization for avoiding medical care.

The publication in JAMA found that people with a body mass index (BMI) categorized as overweight had 6% less risk of death than people of lower weight. For people with all levels of obesity, investigators found an 18% higher risk of death.

For their systematic review and meta-analysis, Katherine Flegal and colleagues at the Centers for Disease Control and Prevention examined nearly 100 studies with close to three million people from the US, Canada, China, Japan, Israel, Brazil, Australia, and other countries.

Some have taken the researchers to task regarding this study. Epidemiologist Walter Willett of the Harvard School of Public Health has been harshest, calling the study a pile of rubbish. Willett has two primary issues with the study. First, he states that it is not helpful to look simply at how BMI influences the risk of premature death without taking health or fitness into account. Some people may be thin because they are ill, so they are at higher risk of death. The study did not control for this. Second, the analysis did not address the more important issue of quality of life. If an overweight person does live longer, is this a benefit or is he or she living with the burden of chronic diseases?

Steven Hymsfield, Executive Director of the Pennington Biomedical Research Center in Louisiana, says this study does not end the debate over whether a little extra body fat could be a good thing. But he says it does illustrate that the relationship between weight and health may be more complicated than just a simple calculation. Hymsfield also points out that determining a person’s BMI is only one step in figuring out future health risks. Body mass index is an imperfect measure of the risk of mortality, said Samuel Klein, Director of the Center for Human Nutrition at Washington University School of Medicine in St. Louis. Factors like blood pressure, cholesterol, and blood sugar need to be considered as well.

Click here to read a New York Times article about the JAMA paper, click here to read the JAMA publication itself, and click here to read the Campos editorial.

Jeff Isom Arguing with Umpire, image © Wikimedia Commons