These nutrients are digested into simpler compounds. Carbohydrates are used for energy (glucose). Fats are used for energy after they are broken into fatty acids. Protein can also be used for energy, but the first job is to help with making hormones, muscle, and other proteins.
Nutrients needed by the body and what they are used for
Type of nutrient
Where it is found
How it is used
Carbohydrate (starches and sugars)
Milk and yogurt
Foods with sugar
Broken down into glucose, used to supply energy to cells. Extra is stored in the liver.
Nuts and seeds
Broken down into amino acids, used to build muscle and to make other proteins that are essential for the body to function.
Broken down into fatty acids to make cell linings and hormones. Extra is stored in fat cells.
After a meal, the blood sugar (glucose) level rises as carbohydrate is digested. This signals the beta cells of the pancreas to release insulin into the bloodstream. Insulin helps glucose enter the body's cells to be used for energy. If all the glucose is not needed for energy, some of it is stored in fat cells and in the liver as glycogen. As sugar moves from the blood to the cells, the blood glucose level returns to a normal between-meal range.
Several hormones and processes help regulate the blood sugar level and keep it within a certain range (4.0 mmol/L to 7.0 mmol/L). When the blood sugar level falls below that range, which may happen between meals, the body has at least three ways of reacting:
Cells in the pancreas can release glucagon, a hormone that signals the body to produce glucose from glycogen in the muscles and liver and release it into the blood.
When glycogen is used up, muscle protein is broken down into amino acids. The liver uses amino acids to create glucose through biochemical reactions (gluconeogenesis).
Fat stores can be used for energy, forming ketones.
Other hormones can raise the blood sugar level, including epinephrine (also called adrenaline) and cortisol released by the adrenal glands and growth hormone released by the pituitary gland.
Current as of:
July 28, 2021
Author: Healthwise Staff Medical Review: E. Gregory Thompson MD - Internal Medicine Adam Husney MD - Family Medicine Kathleen Romito MD - Family Medicine Rhonda O'Brien MS, RD, CDE - Certified Diabetes Educator Colleen O'Connor PhD, RD - Registered Dietitian
Medical Review:E. Gregory Thompson MD - Internal Medicine & Adam Husney MD - Family Medicine & Kathleen Romito MD - Family Medicine & Rhonda O'Brien MS, RD, CDE - Certified Diabetes Educator & Colleen O'Connor PhD, RD - Registered Dietitian
Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
If you have questions about physical activity or exercise, call 8-1-1 (or 7-1-1 for the deaf and heard of hearing) toll-free in B.C. Our qualified exercise professionals are available Monday to Friday from 9am to 5pm Pacific Time. You can also leave a message after hours.
Translation services are available in more than 130 languages.
HealthLinkBC’s qualified exercise professionals can also answer your questions by email.
If you have any questions about healthy eating, food, or nutrition, call 8-1-1 (or 7-1-1 for the deaf and hard of hearing) toll-free in B.C. You can speak to a health service navigator who can connect you with one of our registered dietitians, who are available 9am to 5pm Monday to Friday. You can also leave a message after hours.
Translations services are available in more than 130 languages.
HealthLinkBC Dietitians can also answer your questions by email.