Ever look at the nutrition label on a package of a certain food in the grocery store and are horrified by the amount of fat in it? You place it back on the shelf and think, “I can’t eat that, I’ll be huge.”

You then peruse the rest of the aisles picking up your cereal, granola bars, tomato sauce, etc. Those don’t have much fat in it, so you’re good.

Sound familiar? This is how a lot of people think, but it’s actually wrong. This might be surprising to some but fat doesn’t make you fat. The real culprit to making you put on a few pounds? Sugar. And sugar hides in a lot of unexpected foods that you’re likely eating in replacement of the high-fat ones—like that cereal, granola bars, and tomato sauce you just loaded up your shopping cart with.

Fat vs. sugar

This has actually been an ongoing debate since the 1990s, where the “low-fat” and “no fat” craze began. But when you look at the most recent science, people who limit their fat intake actually don’t have much to show in terms of weight loss.

“There is one thing we know about fats,” says Aaron Carroll, a professor of pediatrics at the Indiana University School of Medicine. “Fat consumption does not cause weight gain. To the contrary, it might actually help us shed a few pounds.”

Because high-fat foods are able to fill you up more substantially than foods with less fat, people tend to snack less and therefore can actually lose weight by eating more fat. Interesting, huh?

To help shed some light on this phenomenon, scientists studied almost 50,000 women over the course of eight years, having about half of them limit their fat. And guess what? They didn’t lose much weight, if any.

The reason is likely because a lot of low-fat foods are high in sugar and carbs. So when you limit your fat intake, you’re risking eating more of these kinds of foods. And that’s no coincidence: A review of 50 studies related to diet and weight gain published in the journal Food and Nutrition Research found that, on average, the more refined grains (cereal, granola bars, etc.) a participant ate, the more weight they gained.

“Our body converts all processed carbs, even wheat bread, into sugar,” says Mark Hyman, MD, Director of the Center for Functional Medicine. “When blood sugar rises, insulin spikes and drives all our body’s fuel into fat cells, especially around the belly. This triggers more hunger, cravings and overeating.”

That said, all fats aren’t created equal. You want to focus on eating monounsaturated fats, which include foods such as avocados, olive oil, nuts and seeds. Limit foods high in saturated fat, which include meats, butter, and cheese, and avoid the “bad” kind of fat, trans fat, such as cookies, cake, and frozen foods.

We know that’s a lot of info on fat, but the gist of it is that we shouldn’t fear eating fat. Limit sugar and eat your fats and you’re good to go!

Did you know that sugar is worse than fat? Which do you eat more of?