by Joseph Coletti
Senior Fellow, Fiscal Studies, John Locke Foundation
“Everything you know about obesity is wrong.” Whether you believe fat people are failures, skinny people are health, diets work, or exercise will make you thin, it is not necessarily true.
Since 1959, research has shown that 95 to 98 percent of attempts to lose weight fail and that two-thirds of dieters gain back more than they lost. The reasons are biological and irreversible. As early as 1969, research showed that losing just 3 percent of your body weight resulted in a 17 percent slowdown in your metabolism—a body-wide starvation response that blasts you with hunger hormones and drops your internal temperature until you rise back to your highest weight. Keeping weight off means fighting your body’s energy-regulation system and battling hunger all day, every day, for the rest of your life.
Studies have found that anywhere from one-third to three-quarters of people classified as obese are metabolically healthy. They show no signs of elevated blood pressure, insulin resistance or high cholesterol. Meanwhile, about a quarter of non-overweight people are what epidemiologists call “the lean unhealthy.” A 2016 study that followed participants for an average of 19 years found that unfit skinny people were twice as likely to get diabetes as fit fat people.
Healthy behaviors matter more than “healthy” weight and yet everything points to fat:
physicians are often required, in writing, to prove to hospital administrators and insurance providers that they have brought up their patient’s weight and formulated a plan to bring it down—regardless of whether that patient came in with arthritis or a broken arm or a bad sunburn. Failing to do that could result in poor performance reviews, low ratings from insurance companies or being denied reimbursement if they refer patients to specialized care.
There are multiple theories about the roles of fat, sugar, other carbohydrates, processed foods, physical activity in disease and weight. Whatever the true cause of health problems, worrying about weight will not improve them. It only leads to shame and bad public policies.