Macro Nutrient Diet

You may know about carbs, protein and fat, but you may not understand the importance of each one in your diet. As macronutrients, carbs, protein and fat are the substances in food that your body needs in the greatest quantities. The macronutrients supply your body with energy, promote metabolism and help ensure that your body functions properly. While there is no macronutrient diet, U.S. dietary guidelines recommend balancing your macronutrient intake to promote good health and meet essential nutrient needs.

Close-up of a baked salmon filet beside fresh broccoli. (Image: Lilyana Vynogradova/iStock/Getty Images)

Carbohydrates: Primary Source of Energy

As your body's primary source of fuel, carbohydrates are the macronutrient needed in the largest amount. The Institute of Medicine states that 45 percent to 65 percent of your calories should come from carbohydrates to ensure you get the nutrients your body needs for good health. Your body also needs an adequate supply of carbohydrates in order for your brain, kidneys and central nervous system to function properly. Starches -- including bread, cereal and potatoes -- fruit, milk and yogurt are the primary sources of carbohydrates in your diet. Vegetables, beans, nuts and seeds also contain carbohydrates, but in lesser amounts.

Protein, for More Than Muscles

Most Americans do not have a problem getting enough protein in their diet, according to the McKinley Health Center. Protein is important for tissue repair, making hormones and enzymes, immune health and preservation of lean body mass. Your body also uses protein for energy when you do not eat enough carbs. Institute of Medicine advises you to get 10 percent to 35 percent of your calories come from protein. Good sources of protein include meat, poultry, seafood, dairy foods, soy, beans and nuts, while grains and vegetables supply smaller amounts.

Fat for Good Health

Fat has a bad rap, but it is an essential nutrient. Like carbohydrates, fat is an important, and concentrated, source of energy. It is also needed for you to absorb the fat-soluble vitamins A, D, E and K. Structurally, adequate fat intake provides cushioning for your organs and is needed to make cell membranes. The Institute of Medicine states that 20 percent to 35 percent of your calories should come from fat. Fat in your diet comes from meat, poultry, dairy foods, eggs, nuts, oils and butter. For better health, consume mostly unsaturated fats, such as oils, nuts, seeds and avocados, as opposed to the saturated fat found in meat, butter and dairy foods.

Balancing Your Meals

Now that you know about the importance of each of the macronutrients in your diet, you need to know how to fit them into your diet. The U.S. Department of Agriculture's MyFoodPlate, which is meant to represent a dinner plate, offers a pictorial of how to balance your intake of carbs, protein and fat for good health. MyFoodPlate is divided into four sections, with one section filled with vegetables, one with fruit, one with grains -- where at least half should come from whole grains such as oats or whole-wheat bread -- and one for protein. On the side is your serving of dairy. For example, a healthy and balanced meal might include steamed broccoli, fresh strawberries, brown rice and grilled salmon with a side of nonfat yogurt.