Understanding Essential Nutrients

Essential Nutrients

Carbohydrates, proteins, and lipids are needed in significant amounts, while vitamins, minerals, and water are also crucial. Most foods are concentrated sources of one or two nutrients.

Food Groups

Foods are typically classified into five main groups:

• Grains
• Vegetables
• Fruits
• Milk
• Meat and Beans

Calories represent energy.

Carbohydrates

Carbohydrates provide us with ATP (energy).

• Two most important types: fructose (easy to absorb because it is a monosaccharide) and glucose (also a monosaccharide and the main carbohydrate in the blood).
• Other types: sucrose, maltose, and lactose. These are more difficult to absorb because they are disaccharides (two molecules linked).

Polysaccharides (Hard to Digest)

Polysaccharides are composed of many monosaccharides linked together.

• Examples: cellulose (a polysaccharide) found in vegetables and starch (another polysaccharide) found in grains.

Proteins

Proteins are the major structural and functional material in body cells.

• Consist of amino acids, which are of two types: essential amino acids (obtained from food) and nonessential amino acids (made by the body).

If carbohydrates are absent, protein is used for ATP, which can lead to acidification in the body.

Lipids

Lipids are organic compounds insoluble in water.

• Include: fats (most common are triglycerides used for energy), oils, and waxes.
• Fats cannot be absorbed as a unit; they must be broken down into glycerol and fatty acids.
• Fats are classified as saturated fatty acids (all carbon atoms connected by single bonds) and unsaturated fatty acids (have at least one double bond between carbon atoms).
• Fat reserves store energy.

Vitamins

Vitamins are organic molecules that act as coenzymes (activating enzymes and enabling them to function).

• Vitamins are either water-soluble or fat-soluble. Water-soluble vitamins (B, C, etc.) can be excreted from the body, while fat-soluble vitamins (A, D, E, K) are stored and not easily excreted.
• Deficiency Diseases:
  • Little Vit. A: Retarded growth
  • Little Vit. B: Beriberi
  • Little Vit. C: Scurvy
  • Little Vit. D: Rickets
  • Little Vit. E: Anemia in newborns
  • Little Vit. K: Hemorrhages

Minerals

Minerals are inorganic substances used to build certain body structures.

• Examples: calcium, iron (helps in the production of hemoglobin), sodium, potassium (important for growth), etc.
• They can be excreted in urine.

Water

Water makes up more than 90 percent of the fluid part of the blood.

• Functions include: avoiding dehydration, regulating body temperature, and helping carry away wastes.