You know that protein boosts satiety and helps refuel your muscles after you work out, so you're always sure to load up on chicken, beef, turkey, and other meats at the grocery store. But according to a new University of Adelaide study, your protein addiction may be the very reason you can't shed that unwanted belly fat—especially if your primary source of the nutrient is meat.
To come to this finding, researchers reviewed the obesity prevalence in 170 countries. As they dug through the data, they found that the nations with the highest obesity rates also had the greatest ease of access to sugar and meat. While you probably already knew that eating too much of the sweet stuff was bad for your belly, it's a lesser-known fact that too much protein can have similar waist-widening effects. Here's what you need to know: On average, our bodies can synthesize about 30 grams of protein at a time, which is what you'd find in a 3-ounce steak or a 4-ounce piece of chicken. (For some context, you'd have to eat 3.75 cups of quinoa or nearly 2 cups of kidney beans to take in that much protein—which is why meat is the bad guy, not just protein-filled foods in general.) When you eat too much protein in one sitting, it isn't packed on as budging biceps. It's stored as fat while the excess amino acids are excreted.
So, now let's marry all this information with an example: Suppose you were to eat a ½ cup of quinoa with a 4-ounce chicken breast. Then, you wash it all down with a cup of skim milk. Your meal's total protein intake would be a whopping 48 grams! While 30 of those grams would be used to fuel your muscles, the excess 18 grams would likely wind up being converted and stored as fat. Eek! This isn't to say you should only eat vegan foods, but you might want to consider reducing the amount of meat in your diet to ensure you don't take in more protein than your body needs.
Eat This! Tip
A few times per week, swap out the meat in your lunch salad for a plant-based protein like kidney beans, which has 7 grams of protein per half-cup. This leaves you with 23 grams to spare on other protein-rich foods like quinoa and hard-boiled eggs.