Macronutrients
Macronutrients are nutrients required in relatively large amounts by the human body to provide energy, support growth, and maintain function. The term typically includes carbohydrates, proteins, and fats; water is often discussed alongside macronutrients because it is needed in large quantities for hydration and metabolic processes. Each macronutrient contributes energy: carbohydrates about 4 kcal per gram, proteins about 4 kcal/g, and fats about 9 kcal/g.
Carbohydrates supply the body’s primary energy source and include sugars, starches, and dietary fiber. Digested carbohydrates
Proteins provide amino acids for tissue maintenance, immune function, and the synthesis of enzymes and hormones.
Fats provide concentrated energy and are necessary for the absorption of fat-soluble vitamins and the function
Dietary guidelines often express macronutrient needs as proportions of total energy, known as the Acceptable Macronutrient