Although dietary fat has more energy (calories) per gram than protein and carbohydrates, your body has a more difficult time pulling the energy out of fatty foods than out of foods high in protein and carbs.

Imagine a chain of long balloons — the kind people twist into shapes that resemble dachshunds, flowers, and other amusing things. When you drop one of these balloons into water, it floats. That’s exactly what happens when you swallow fat-rich foods. The fat floats on top of the watery food-and-liquid mixture in your stomach, which limits the effects of lipases, the enzymes that break fats apart so you can digest them. As a result, fat is digested more slowly than proteins and carbohydrates, so you feel fuller, a condition called satiety (pronounced say-ty-eh-tee) longer after eating high-fat food