https://highline.huffingtonpost.com/articles/en/everything-you-know-about-obesity-is-wrong/
About 40 years ago, Americans started getting much larger. According to the Centers for Disease Control and Prevention, nearly 80 percent of adults and about one-third of children now meet the clinical definition of overweight or obese. More Americans live with “extreme obesity“ than with breast cancer, Parkinson’s, Alzheimer’s and HIV put together.
And the medical community’s primary response to this shift has been to blame fat people for being fat. Obesity, we are told, is a personal failing that strains our health care system, shrinks our GDP and saps our military strength. It is also an excuse to bully fat people in one sentence and then inform them in the next that you are doing it for their own good. That’s why the fear of becoming fat, or staying that way, drives Americans to spend more on dieting every year than we spend on video games or movies. Forty-five percent of adults say they’re preoccupied with their weight some or all of the time—an 11-point rise since 1990. Nearly half of 3- to 6- year old girls say they worry about being fat.
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The second big lesson the medical establishment has learned and rejected over and over again is that weight and health are not perfect synonyms. Yes, nearly every population-level study finds that fat people have worse cardiovascular health than thin people. But individuals are not averages: 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. Habits, no matter your size, are what really matter. Dozens of indicators, from vegetable consumption to regular exercise to grip strength, provide a better snapshot of someone’s health than looking at her from across a room.
The terrible irony is that for 60 years, we’ve approached the obesity epidemic like a fad dieter: If we just try the exact same thing one more time, we'll get a different result. And so it’s time for a paradigm shift. We’re not going to become a skinnier country. But we still have a chance to become a healthier one.
Long read, but the tl;dr is, when we address obesity through programs that promote better nutrition and more exercise, people don't get skinnier, but they do get healthier and have better outcomes.