Do nuts make you fat? Short answer: NoAs much as 75% of a nut is fat. But eating fat doesn't necessarily make you fat. The bigger factor leading to weight gain is portion-size. Luckily, nuts are loaded with healthy fats that keep you full. They're also a good source of protein and fiber. One study even found that whole almonds have 20% less calories than previously thought because a lot of the fat is excreted from the body.