Which macronutrient has the highest caloric value per gram?

Fat has the highest caloric value per gram compared to other macronutrients, providing approximately 9 calories per gram. This higher caloric density is due to the chemical structure of fats, which includes long chains of carbon and hydrogen atoms that store more energy than carbohydrates or proteins.

Carbohydrates and proteins each provide around 4 calories per gram. Vitamins, while essential for various bodily functions, do not provide caloric energy as they are considered micronutrients. Therefore, when considering the energy yield from different macronutrients, fat stands out as the most concentrated source of energy, making it crucial for those needing higher calorie intake or looking for energy-dense food options.