The macronutrient that provides the most energy per gram is fat, yielding approximately 9 calories per gram. This is significantly higher than carbohydrates and proteins, each providing about 4 calories per gram. Fats are essential for energy storage, cellular function, and hormone regulation in the body. While they are calorie-dense, incorporating healthy fats, such as those from avocados, nuts, and fish, is vital for balanced nutrition. Understanding the caloric content of macronutrients aids individuals in making informed dietary choices to support energy needs and overall health.