Name the three macronutrients that the human body requires for energy.

The three macronutrients that provide the human body with energy are protein, carbohydrates, and fat. They are nutrients required in relatively large amounts, and each has a different primary role in metabolism and body maintenance.

Carbohydrates are commonly converted into glucose, an especially important fuel for the brain and working muscles. Protein is built from amino acids and is best known for supporting muscle, enzymes, hormones, and tissue repair, although the body can also use it for energy. Fat supplies concentrated energy, forms part of cell membranes, cushions organs, and helps the body absorb vitamins A, D, E, and K.

A frequent mix-up is treating fiber or vitamin C as one of the energy-providing macronutrients. Fiber is a type of carbohydrate that is not fully digested, while vitamin C is a micronutrient. On average, carbohydrates and protein provide about 4 calories per gram, and fat provides about 9 calories per gram.