Which nutrient yields the most energy per gram?

Which nutrient yields the most energy per gram?

• A. Carbohydrates
• B. Vitamins
• C. Proteins
• D. Lipids

Answer: (D)

Energy density across macronutrients shows that lipids produce the most energy per gram. Lipids yield about 9 kilocalories per gram, which is higher than the roughly 4 kcal per gram provided by both carbohydrates and proteins. This higher energy yield comes from the chemical structure of fats, which contains many carbon-hydrogen bonds that release a lot of energy when oxidized during metabolism. Vitamins, in contrast, do not supply usable energy; they act as cofactors and helpers in metabolic processes rather than as calorie sources. So, among the options, fats deliver the greatest energy per gram.

Energy density across macronutrients shows that lipids produce the most energy per gram. Lipids yield about 9 kilocalories per gram, which is higher than the roughly 4 kcal per gram provided by both carbohydrates and proteins. This higher energy yield comes from the chemical structure of fats, which contains many carbon-hydrogen bonds that release a lot of energy when oxidized during metabolism. Vitamins, in contrast, do not supply usable energy; they act as cofactors and helpers in metabolic processes rather than as calorie sources. So, among the options, fats deliver the greatest energy per gram.