Macronutrients for Optimal Human Growth & Health

Macronutrients are nutrients needed in large amounts by the human body. In contrast, micronutrients---vitamins and minerals---are needed in very small amounts.

Types

• The three main types of macronutrients are carbohydrates (including sugars and dietary fiber) and protein, which provide four calories per gram, and fat (including saturated and unsaturated fat), which provides nine calories per gram.

Carbohydrates

• Carbohydrates should make up about half of our daily caloric intake, according to the USDA. Our body breaks them down into glucose, which is necessary to give our body energy and to keep the central nervous system functioning.

Fiber

• Fiber, a form of complex carbohydrate that our bodies cannot fully digest, helps move waste through the intestines and can reduce the risk of constipation and colon cancer.

Protein

• About a tenth to a third of our daily calories should come from protein, which is necessary for building lean muscle, repairing tissue and strengthening our immune systems.

Fat

• About a fifth to a third of our daily calories should come from fat, which promotes normal growth, builds cell membranes and helps us absorb important vitamins such as A and D.