How many calories per gram does dietary fat supply compared to carbohydrates and proteins?
About nine calories per gram
Dietary fat is characterized by being the most energy-dense macronutrient available in the human diet. This high caloric concentration is a direct result of its chemical composition. Specifically, fats yield approximately nine calories for every single gram consumed. In sharp contrast, the other two primary macronutrients—carbohydrates and proteins—provide significantly less energy per gram, yielding only about four calories per gram each. This substantial difference in caloric yield is the fundamental reason why foods high in fat content can contribute very quickly to a calorie surplus if portion sizes are not strictly managed, which often leads to the confusion between the nutrient fat and the descriptive term 'fattening'.
