US Adult Obesity Rate May Hit 42% Before Plateauing


photo: Thomas Tringale/Creative Commons

If you thought the obesity epidemic in the United States couldn't get much worse, new research from Harvard University projects that the national obesity rate won't plateau until at least 42% of adults are obese, something which may not happen for another four decades. Currently and for the past five years slightly over one-third of adults in the country are obese, with another third being overweight. Applying mathematical modeling to 40 years of data from the Framingham Heart Study, the researchers came to a different conclusion than recent assertions that the obesity rate had already leveled out. At the beginning of that time period, obesity gripped 14% of the study participants.

The report authors note that non-social factors in obesity--the usual culprits of bad diet (either by choice, lack of access to healthy food, lack of awareness, etc) and increasingly sedentary lifestyles--remain the most important elements of our expanding collective waistline.

However, "social norms are changing the propensity for becoming obese by non-social mechanisms, and also magnifying the effect that obese individuals have on their non-obese contacts."

Study lead author Alison Hill adds,

Our analysis suggest that while people have gotten better at gaining weight since 1971, they haven't gotten any better at losing weight. Specifically, the rate of weight gain due to social transmission has grown quite rapidly.

Social transmission of obesity?

The study found that a non-obese adult American has a 2% chance of becoming obese in any given year. For every person with whom you regularly associate that rate increases by 0.5%--if you know four obese people, your chance of expanding into obesity doubles. This has increased in recent decades. Conversely, if you are already obese, in any given year your statistical chances of losing enough weight to shrink back into the overweight category are 4%--a figure that has remained largely unchanged since 1971.

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Graph of the Day: Obesity Rates Around The World
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Tags: Diet | United States

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