Which macronutrient provides the most calories per gram?

Which macronutrient provides the most calories per gram?

• A. Carbohydrates
• B. Proteins
• C. Fats
• D. Alcohol

Answer: (C)

Fats deliver the most calories per gram because they have a highly energy-dense chemical structure. Each gram of fat yields about 9 kilocalories, due to the many energy-rich carbon-hydrogen bonds in fatty acids. In contrast, carbohydrates and proteins provide about 4 kilocalories per gram, and alcohol provides about 7 kilocalories per gram but isn’t considered a macronutrient like fats, carbs, or protein. So, among the macronutrients, fats have the highest energy density.

Fats deliver the most calories per gram because they have a highly energy-dense chemical structure. Each gram of fat yields about 9 kilocalories, due to the many energy-rich carbon-hydrogen bonds in fatty acids. In contrast, carbohydrates and proteins provide about 4 kilocalories per gram, and alcohol provides about 7 kilocalories per gram but isn’t considered a macronutrient like fats, carbs, or protein. So, among the macronutrients, fats have the highest energy density.