Bears, Famine, and Dieting Failure
I know it’s been three super research-heavy newsletters in a row, so I thought today we’d do something different. About a month ago I gave a talk to a group of weight-neutral doctors. We were talking about the research and possible mechanisms around the near-complete failure rate of intentional weight loss, and one of the doctors asked me for ideas to talk about this with patients who were still invested in weight loss. I gave her this and I just got an email saying that her patients love it asking if I have it written down anywhere that she could link to. Now I do…
Note: This is a very stripped down story to create a simple, basic explanation. Also, it is also in no way meant to make light of famine, food scarcity, and hunger, which impact people around the world and do the most harm to the most marginalized (including children.)
The thing about intentional weight loss is that research shows that almost everyone loses a little weight short-term, but then almost everyone gains back to (or past) their baseline long-term. This is a two-part biological response to intentional weight loss attempts. Weight loss companies make billions by taking credit for the first part, and then blaming their clients (and getting clients to blame themselves, and everyone else to blame them,) for the second part of the same biological response.
Your body doesn’t understand that there is a certain size and shape that brings with it increased social capital. Your body can’t imagine a situation in which it is hungry and there is food, but you won’t feed it. And so when your body sends hunger signals, but you ignore them, it assumes that there is no food available. Your body thinks “No problem, I’ve evolved to survive famine, give me just a bit to get those systems online.” So while you are losing a bit of weight short-term, your body starts changing physiologically, doing things like slowing down metabolism and manipulating hormone levels to make you think about food all the time.
In the meantime, you go run on a treadmill. Your body now thinks there is a famine AND you have to run from bears. But, again, your body is like “No problem, surviving is my thing, I’ve got this.” So it makes more and greater physiological changes (since, what with the famine and the running from bears, it wants to make sure that you don’t forget to eat.) Basically, your body is hard at work doing everything it can to become a weight regaining, weight maintaining machine.
At the end of this process your body is biologically different than it was when you started, and biologically different than a body that has never dieted, because it now worries that it will experience another famine and bear situation. Bodies are still biologically different even a year or more after someone stops dieting.
It’s not about people lacking willpower or “just going back to their old habits.” It’s about the fact that starvation is unsustainable (dieting requires that you eat less fuel than you need so that your body will consume itself and become smaller) especially when the body reacts by working as hard as it can to make sure your weight loss attempts fail.
The bottom line is that nobody can produce research for any intentional weight loss method (call it a diet, call it a lifestyle change, call it whatever) that succeeds in creating long-term, significant weight loss for more than a tiny fraction of people, which means that weight loss doesn’t meet the requirements of an ethical, evidence-based intervention.
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*Note on language: I use “fat” as a neutral descriptor as used by the fat activist community, I use “ob*se” and “overw*ight” to acknowledge that these are terms that were created to medicalize and pathologize fat bodies, with roots in racism and specifically anti-Blackness. Please read Sabrina Strings’ Fearing the Black Body – the Racial Origins of Fat Phobia and Da’Shaun Harrison’s Belly of the Beast: The Politics of Anti-Fatness as Anti-Blackness for more on this.