Major Nutrients in Food

Topic Overview

The major nutrients—protein, carbohydrate, and fat—provide the body with energy. This energy keeps your heart beating, your brain active, and your muscles working. The energy is measured in calories.

Nutrients in foods

Nutrient

Function

Some sources

Protein has 4 calories per gram

Provides energy; builds and repairs body cells; part of various enzymes, hormones, and antibodies

Meat, poultry, fish, eggs, beans, lentils, tofu, milk and milk products, grains, seeds and nuts

Carbohydrate has 4 calories per gram

Provides energy needed by the brain, nervous system, and red blood cells

Breads, cereal grains, pasta, rice, fruit, starchy vegetables, milk, sugar

Fat has 9 calories per gram

Provides energy; carries fat-soluble nutrients (vitamins); part of cell membranes, membranes around nerves, hormones, bile (for fat digestion)


Meat and poultry, some fish, milk and milk products that are not fat-free, nuts and seeds, oils, butter, margarine, salad dressing, some candy, some desserts

Related Information

Credits

ByHealthwise Staff
Primary Medical Reviewer Anne C. Poinier, MD - Internal Medicine
Adam Husney, MD - Family Medicine
Kathleen Romito, MD - Family Medicine
Specialist Medical Reviewer Rhonda O'Brien, MS, RD, CDE - Certified Diabetes Educator
Colleen O'Connor, PhD, RD - Registered Dietitian

Current as ofMarch 29, 2018

Is it an emergency?

If you or someone in your care has chest pains, difficulty breathing, or severe bleeding, it could be a life-threatening emergency. Call 9-1-1 or the local emergency number immediately.
If you are concerned about a possible poisoning or exposure to a toxic substance, call Poison Control now at 1-800-567-8911.

Thanks to our partners and endorsers: