Weight loss's link to better health questioned

By Jennifer LaRue Huget

We as a nation have put a lot of stock into the notion that being (or becoming) thin equates to better health and longer lives.

But some experts have called into question whether that connection -- or, conversely, the connection between overweight and poor health -- is all that strong, and even whether it exists at all.

One of the leading voices in the debate is Linda Bacon, associate nutritionist

in the University of California, Davis department of nutrition. Today she and a colleague, Lucy Aphramor, released a report in the online Nutrition Journal reviewing the key assumptions regarding the link between weight status and health. Citing findings from about 200 studies, they make a compelling case that overweight in and of itself does not pose a major health risk. (In fact, in some cases being overweight appears to reduce risk of certain diseases and conditions such as osteoporosis.)

Bacon's report suggests that changing eating and physical activity behaviors without regard for their effect on weight is more likely to improve our health, and that focusing on weight loss alone can have damaging consequences. For instance, "weight cycling," the all-too-common experience of repeatedly gaining and losing weight, can cause bodily inflammation, a risk factor for cardiovascular disease and cancer. Emphasis on weight loss can also inflict psychological and emotional stress, which can contribute to physical disease, the report notes.

Bacon repeats her observation that much health policy is built around the assumption that overweight causes such conditions as Type 2 diabetes and cardiovascular disease. In fact, she asserts (with supporting study references), evidence of cause-and-effect relationships between overweight and such health outcomes is scant:

While it is well established that obesity is associated with increased risk for many diseases, causation is less well-established. Epidemiological studies rarely acknowledge factors like fitness, activity, nutrient intake, weight cycling or socioeconomic status when considering connections between weight and disease. Yet all play a role in determining health risk. When studies do control for these factors, increased risk of disease disappears or is significantly reduced. (This is less true at statistical extremes.) It is likely that these other factors increase disease risk at the same time they increase the risk of weight gain.

And there's this:

Except at statistical extremes, body mass index (BMI) -- or amount of body fat -- only weakly predicts longevity [32]. Most epidemiological studies find that people who are overweight or moderately obese live at least as long as normal weight people, and often longer.

I've interviewed Bacon before and reported on her "Health at Every Size" initiative several times. Her stance often meets with derision; it's hard for people to shake the belief that overweight is the root of many of our nation's health woes. But decades of dieting haven't paid off for Americans; twice as many of us are overweight or obese than otherwise, despite years of being told we need to slim down. Maybe it's time to look at the situation from a different perspective. Please take a few minutes to read Bacon's report and let me know what you think.