Are You Terrible at Dieting? Science Has a New Reason for It


Scarlett Rose Leithold

This just in: We are biologically wired to suck at dieting.

Personally, I know I’m awful at it. Every time my weight fluctuates a few pounds higher than I’d like, my first thought is always, Ugh, how can I lose this weight without dieting? What can I say? I hate feeling hungry.

According to a new report from Huffington Post, our collective aversion to dieting and frequent inability to keep weight off is innate. In other words, it’s not our fault—it’s our brain’s fault.

Here’s how: We all have this part of our brains called the reptilian brain, which evolved early in humans and is very primitive. The reptilian brain is in charge of involuntary actions, the regulation of food intake, and our base survival mechanism. It’s also the first part of the brain to respond to stress. When something trying happens (whether that be physical stress like a grizzly bear approaching or emotional stress like a breakup), the reptilian brain freaks out and takes over in an attempt to help us survive. “This is why it’s very hard to ‘think logically’ when in these situations,” writes Vania Phitidis. “The reptilian brain can’t distinguish between emotional and physical pain, so it sends out danger signals to other parts of the brain, which means the whole body goes into a state of protective stress.”

What does this have to do with dieting, you ask?

Going on a diet normally means restricting food, either calories or entire food groups (like dairy or carbs) or both. We also tend to exercise more when we diet.

When we restrict our food and ignore our hunger, the reptilian brain thinks it’s in danger of famine and goes into that panicky survival mode. Because the reptilian brain is basically stuck in the caveman era, it doesn’t understand that we’re not actually starving. As a result, it sends a signal to the body to slow down our metabolism and stop burning food so quickly, as if we’re living in the wilderness 10,000 years ago and might not see food for a week.

If you manage to stick this torture out, once you finish your diet, the reptilian brain thinks Hooray! The famine is over! and instructs your body to feast. That’s why your “cheat days” are basically just animalistic pizza marathons—it’s just your reptilian brain trying to keep you alive.

So the next time you decide you want to lose weight, give your reptilian brain a break and don’t starve it. Instead, feed it satisfying, nutritious foods that will help you slim down without tricking anyone into thinking there’s a famine coming.

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