Nutrients and normal blood sugar control

The body needs three main nutrients to function properly-carbohydrate, protein, and fat. These nutrients are digested into simpler compounds. Breads, grains, vegetables, and sugary foods are carbohydrate that is converted to glucose, one of many types of sugar molecules produced when carbohydrate is digested in the stomach and intestines. Similarly, the body breaks down protein into amino acids and fat into fatty acids, all to store energy for the body.

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)	Breads Grains Vegetables Foods with sugar	Broken down into glucose, used to supply energy to cells
Protein	Meat Legumes Egg whites	Broken down into amino acids, used to build muscle and to manufacture other proteins that are essential for the body to function
Fat	Oils Butter Egg yolks Animal products	Broken down into fatty acids, used to manufacture cell linings and hormones and to serve as food stores for future needs

After a meal, the blood sugar (glucose) level rises as carbohydrate is digested. This stimulates 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 tightly within a safe range (80 mg/dL to 120 mg/dL). When the blood sugar level falls below the desirable range, which may happen between meals, the body has at least three ways of responding:

• Cells in the pancreas release glucagon, a hormone that stimulates the body to produce glucose from glycogen in the muscles and liver and release it into the blood.
• Once glycogen is used up, muscle protein itself is broken down. The liver uses the resulting amino acids to create glucose through a series of biochemical reactions (gluconeogenesis).
• Fat stores are also used for energy, forming compounds called ketones.

Other hormones may also intervene to 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.