is there a difference between calories in carbohydrates and proteins?
Carbohydrates, proteins, and fats supply 90% of the dry weight of the diet and 100% of its energy. All three provide energy (measured in calories), but the amount of energy in 1 gram (1/28 ounce) differs: 4 calories in a gram of carbohydrate or protein. 9 calories in a gram of fat.