Here’s What Science Says About The Most Popular Diets

Photographed by Fernanda Silva.
Whether they're focused on helping us lose weight, build muscle, or eat like our ancestors, diets have been around for centuries. But, the science behind them is often way more convoluted and contradictory than we realize.  To address that confusion, a study published this week in the Annals of Internal Medicine attempted to quantify how well commercial weight-loss programs actually work. To do so, researchers went through 45 studies that evaluated the efficacy of 32 diets compared to controls.  Out of all those programs — ranging from Atkins to Nutrisystem — only two (two!) had reliable evidence backing up their potential to help people lose weight. Those were Weight Watchers and Jenny Craig, which helped dieters lose an average of 3-5% more of their body weight in a year compared to controls. So, even when these plans work, they do so slowly rather than dramatically. In the background of all of this is the question of whether or not it's really worth it to diet anyway. Harriet Brown, author of Body of Truth: How Science, History, and Culture Drive Our Obsession with Weight — and What We Can Do about It, recently wrote on Slate that if you plan on going on a diet this year, "you’ll likely lose weight in the short term, but your chance of keeping if off for five years or more is about the same as your chance of surviving metastatic lung cancer: 5 percent. And when you do gain back the weight, everyone will blame you. Including you."

On the other hand, just because "fad" diets tend to fail, that doesn't mean all dieting attempts are hopeless, Vox fired back. Instead, it's often the insane goals we and society set for ourselves that lead us to choose the most extreme options — and feel like shit when they don't work out. However, another study recently showed just how far our culture's influence has permeated: Simply being primed to think about physical appearance (using a mirror or an ad) caused participants to snack more. So, it seems like dieting may be an inherently self-defeating task on some level and is almost certainly not a one-size-fits-all scenario. The bottom line is that the best eating plan is whatever feels right for you — especially if that diet is not dieting.

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