For children aged 8 to 12, eating a breakfast high in protein instead of one high in carbohydrates leads to a measurable reduction in hunger and an increase in fullness within a few hours, regardless of their weight.

In children aged 8 to 12, eating a protein-rich breakfast makes them feel less hungry and more full than a carb-rich breakfast, but they still eat the same amount of food at lunch. This shows that feeling fuller doesn't always mean eating less.

The benefits of a high-protein breakfast on hunger and eating habits only showed up after eating it every day for a week — one meal wasn’t enough.

When children aged 8 to 12 eat a breakfast with 18 grams of protein instead of one with 3 grams of protein, their bodies burn more fat and use more energy in the hours after eating, regardless of their weight.

Children who are overweight or obese burn more fat and use more energy after eating a high-protein breakfast than children of normal weight do, suggesting their bodies respond differently to the same meal.

These results only apply to healthy, young, professional adults — we don’t know if they’d work for older people, shift workers, or those with health problems.