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)
Foods with sugar
Broken down into glucose, used to supply
energy to cells. Extra is stored in the liver.
Broken down into amino acids, used to build
muscle and to make other proteins that are essential for the body to
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
Several hormones and processes help regulate the blood sugar level
and keep it within a certain range
(70 mg/dL to 120 mg/dL). 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
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
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
The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.