Mountain Living

REQUIRED FOOD COMPONENTS
2-6. Three major food components are required to maintain a well-functioning body: proteins, fats, and
carbohydrates. These food components provide energy, amino acids, vitamins, fiber, and minerals. All
three components must be provided in the correct proportions to maintain a healthy body.

Protein
Mechanism
2-7. Proteins consist of a large number of amino acid units that are linked together to form the protein.
The amino acids, resulting from digestion of protein, are absorbed through the intestine into the blood.
Function
2-8. Proteins are used to make or replace body proteins (muscle and body tissue).
Sources
2-9. Sources of readily usable animal proteins include eggs, milk, cheese, poultry, fish, and meats. Other
foods such as cereals, vegetables, and legumes also provide amino acids, but these proteins are less
balanced in essential amino acid composition than are meat, egg, or milk proteins.
Minimum Daily Requirement
2-10. The minimum requirement, regardless of physical activity, is 8 ounces of protein daily for a
154-pound man. Since amino acids are either oxidized for energy or stored as fats, consuming excess
protein is inefficient.
Effect on Hydration
2-11. Proteins may increase the water intake needed for urea nitrogen excretion. Protein requires water for
digestion and may facilitate dehydration.
Energy Yield
2-12. Proteins provide the body about four kilocalories of energy per gram.
Digestibility
2-13. Proteins require more energy than fats or carbohydrates to digest.

Fats
Function
2-14. Fats are the body’s natural and most concentrated source of stored food energy.
Sources
2-15. Main sources of fats are meats, nuts, butter, eggs, milk, and cheese.
Minimum Daily Requirement
2-16. Of the total daily caloric intake, 25 to 30 percent may be supplied as fats.
Effect on Hydration
2-17. Fats require more water and oxygen to digest than protein.

26 July 2012

TC 3-97.61

2-3