Which of the following provides the body with 9 calories per gram?

The correct choice is fats, as they provide the body with 9 calories per gram, making them the most calorie-dense macronutrient. Fats play vital roles in the body, including serving as a primary energy source, supporting cell structure, and aiding in the absorption of fat-soluble vitamins (A, D, E, K).

In contrast, proteins and carbohydrates each provide about 4 calories per gram, which means they have a lower caloric density compared to fats. Dietary fiber, which is a type of carbohydrate, typically provides minimal calories because it is not fully digestible by the body. Understanding the calorie content of different macronutrients is essential for nutritional planning and maintaining a balanced diet.