When people eat a meal with less protein than usual, they tend to eat more total calories that day — and this pattern holds up even when accounting for other factors.

How full or hungry people feel doesn’t explain why they eat more or less after choosing their own meal.

When people eating a high-protein diet skip their planned meal and choose something with less protein, they tend to eat about 260 more calories that day.

What you eat in one meal matters more for how many calories you eat that day than how hungry or full you feel.

Eating a meal with less protein makes you eat more calories — but not because you’re hungrier. Something else about the meal is making you eat more.

The day after eating a meal with less protein than usual, people tend to eat about 60 fewer calories than normal.