Boston University Sargent Choice Nutrition Center

The Basic Nutrients in Food


The Basic Nutrients in FoodNearly all the carbohydrate you eat is broken down into blood sugar to provide energy for activity, including brainwork. Carb energy is fast but it doesn’t last. So you crave more when you’re hungry and need to keep supplying it throughout the day.

The key to being satisfied with the right amount of carbohydrate is to choose whole foods whenever you can—fruits, vegetables and whole grains. These whole food sources of carbohydrate combine natural fiber and water to deliver a filling package. On the other hand, processed foods like white bread, jellybeans and even juice have fewer ingredients to fill you up. They make it difficult to recognize that you’ve had enough before you’ve had too much.

Food sources:

  • Starch — Breads, cereals, pasta, crackers, potatoes, beans, peas and lentils
  • Fiber: Two types package up the nutrients found in plants
    • Soluble fiber helps to maintain even blood sugar Oats, barley, beans, peas, nuts, seeds, fruits and vegetables
    • Insoluble fiber promotes regularity and prevents constipationWhole wheat, bran, nuts, seeds, fruits and vegetables
  • Natural sugars — Fruits, vegetables, milk products
  • Added sugars — White, brown and raw sugar; honey, molasses, corn syrup, maple syrup, fructose and dextrose, high fructose corn syrup and malt syrup

To learn more about carbohydrates, see The 6 Major Food Groups.


The Basic Nutrients in FoodProtein provides components for building all types of body cells. So the amount you need increases with body weight and cell-building activity. Most people get more than enough because protein is found in so many foods. But you may not be getting it at the right times. It’s particularly important when your next meal is several hours away. By stabilizing blood sugar just when carbohydrate is running out, protein helps keep you satisfied longer.

Food sources:

  • Animal protein — Beef, veal, poultry, fish, pork, lamb, dairy products and eggs
  • Plant protein — Nuts and nut butters, seeds, beans, peas, lentils and soy products
  • Grains — Breads, cereals, rice, pasta and crackers
  • Vegetables — Starchy and non-starchy vegetables

To learn more about proteins, including which are heart-healthy, see The 6 Major Food Groups.


When your energy needs are high, fats provide an efficient source of energy, delivering 9 calories per gram compared to 4 calories per gram from carbohydrate and protein. They also aid in the absorption of fat-soluble vitamins (A, D, E and K). Fats don’t raise blood sugar very much but increase satisfaction of fast-acting carbohydrates by prolonging the time it takes for your stomach to empty.

You may have assumed all fats are bad because they’re “fattening.” But you need heart-healthy fats in your diet. They not only contribute to good health and good flavor but also help you avoid overeating by keeping you satisfied longer.

Food sources:

Artery-clogging fats

  • Trans-fat — margarine, vegetable shortening, partially hydrogenated oils, deep fried foods and commercially baked cookies, cakes, muffins and pastries
  • Saturated fat — red meats, poultry skin and dark meat, butter, cheese, cream, whole and 2% milk, tropical oils (palm, palm kernel and coconut)

Heart-healthy fats

  • Polyunsaturated fat
    • Omega 6 — Corn, safflower, sunflower and soybean oils
    • Omega 3 — Fish including salmon and sardines, walnuts, cod liver oil, canola and flax seed oil
  • Monounsaturated fat
    • Olive, canola and peanut oils, nuts and nut butters, avocadoes

To learn more about heart-healthy fats, see The 6 Major Food Groups.