Commentary

Obesity Police’s Shaky Science

By Patrick Basham and John Luik
This article appeared in the Baltimore Sun on July 29, 2009.

Why is a thin, male smoker considered a physical role model as president but a full-figured African-American woman is considered an embarrassment as his nominee for surgeon general?

President Barack Obama’s nomination this month of Dr. Regina Benjamin as U.S. surgeon general brought down upon the White House a barrage of criticism from medical “experts” who claim Dr. Benjamin is setting a bad example because of her weight. For example, Dr. Sarah Reed, who religiously keeps her own Body Mass Index in the “underweight” category, was quoted in The Daily Telegraph saying: “Although her credentials speak for themselves, her weight cannot be overlooked. Shame on her!”.

Is Dr. Benjamin too fat to handle the nation’s health? There are three evidence-based public health reasons why worries about her weight are unwarranted.

First, there is little credible scientific evidence that supports the claims that having an overweight or obese BMI leads to an early death. For example, Katherine Flegal of the Centers for Disease Control and Prevention found that in the U.S. population there were more premature deaths among those with BMIs of less than 25 — the so-called normal weight — than those with BMIs in excess of 25.

In fact, the lowest death rates were in the “overweight” category — that is, those with BMIs from 25 to 29.9. Indeed, in this study, Americans who were overweight were those most likely to live the longest.

In the American Journal of Public Health, Professor Jerome Gronniger looked at weight and mortality for each BMI point, rather than simply comparing, as is usually done, mortality across broad categories, such as underweight, normal, overweight and obese. He found that men in the “normal” weight category exhibited a mortality rate as high as that of men in the moderately obese category (BMIs of 30 to 35); men in the “overweight” category clearly had the lowest mortality risk.

Moreover, a new study published in the American Journal of Clinical Nutrition that looked at alternative measures of obesity, such as percentage of body fat, skin fold thickness, waist circumference, and waist-hip ratio, found even less scientific support for the alleged fat-equals-early-death thesis. The authors report that for the intermediate level of each of the alternative measures of obesity, there was a negative link with mortality. In other words, those with a higher waist circumference or a higher percentage of body fat had lower mortality rates.

A second reason why Dr. Benjamin’s weight is a non-issue is because in those studies that have found statistically significant associations between overweight/obesity and premature mortality, the risks are so modest as to be essentially negligible. For example, whereas the reported lung cancer risks for smokers are typically 10 to 20 times higher than for nonsmokers, the death risks for those who are overweight and obese are often closer to only 0.5 above those of normal weight.

Third, contrary to conventional wisdom, the association of overweight and obesity with higher risks for a variety of diseases, such as cancer, diabetes and heart disease is unproven. In part, this is because these diseases have multiple causes.

More strikingly, increases in overweight and obesity have been paralleled by falls in total cardiovascular mortality and mortality from coronary heart disease and stroke, as well as in the prevalence of hypertension and hypercholesterolemia, undermining claims that overweight and obesity lead to higher rates of morbidity.

The case against Dr. Benjamin’s suitability as surgeon general is constructed out of an anti-obesity crusade that has been splashed across so many front pages for so long that no one asks whether it is based on evidence. The questionable science underpinning the criticism of Dr. Benjamin is a smoke screen for an artfully choreographed anti-fat prejudice that, according to the eating disorder statistics, has already taken white women, girls, boys and ethnic minorities as its victims.

The last demographic holdout against “fatism” is the African-American female, who on average is disproportionately heavy. And she is disproportionately comfortable with her weight. The fat police view this fact as simply unacceptable.

Hence, their attack on Dr. Benjamin, which they perceive as an opportunity to lance this particular demographic boil once and for all. Shame on them.

Patrick Basham, a Cato Institute adjunct scholar, is affiliated with the Johns Hopkins University as a lecturer. John Luik is a Democracy Institute senior fellow. They are coauthors of Diet Nation: Exposing the Obesity Crusade.