People who eat more ultra-processed foods tend to consume a smaller proportion of their calories from protein and more from fats and carbohydrates, even though their total amount of protein stays the same, and they end up consuming more total calories.

When healthy young people eat ultra-processed foods that are high in protein and low in carbs, they naturally eat about 200 fewer calories per day than when they eat ultra-processed foods with normal protein and carbs—even if both meals taste the same.

When people eat a diet with only 10% protein, they tend to consume more calories overall because they eat more savory snacks between meals, not because they eat larger meals. This suggests that lower protein levels may trigger more frequent eating starts, not reduced fullness.

Even though people still ate more calories than they burned, eating high-protein, low-carb ultra-processed foods made them much less likely to store excess energy as fat compared to normal-protein ultra-processed foods.

Eating ultra-processed foods with more protein and fewer carbs makes your body burn about 130 extra calories per day just to digest and process the food, even if you’re not moving more.

Eating more protein makes you feel fuller for longer than eating the same amount of carbs or fat, which helps you eat less and manage your weight better.