Chemistry

Carbohydrates

Although used by all cells, carbohydrates are especially important for the normal functioning of the central nervous system, brain and red blood cells. Fiber, an indigestible form of carbohydrate found in whole grain foods, fruits and vegetables, helps to maintain normal bowel movement that reduces risk of constipation, hemorrhoids, diverticulosis and colon cancer. By increasing excretion of cholesterol, fiber may decrease risk of heart disease, and by providing a feeling of fullness, which may help reduce risk of obesity.

Proteins

The proteins in your body carry out many functions, ranging from forming organ tissues to making antibodies that fight infection. They are present in every cell of your body, including muscles, bones, skin, nails and hair, and are critical for synthesis of hormones, enzymes, DNA and RNA. Proteins enable normal growth and development of children and teens, and of the fetus during pregnancy, and they provide a secondary source of energy. Eggs, meat, poultry, fish, soybeans, legumes, milk and dairy products are some of the best sources of protein.

Fats and Lipids

Although fat intake is often associated with weight gain, obesity and risk of heart disease, fat is an essential nutrient required in small amounts to maintain health. Fats are crucial for absorption and transport of fat-soluble vitamins A, D, E and K. They help form and maintain cell membranes, insulate and cushion vital organs and are a concentrated source of energy. Opt for heart-healthy unsaturated fats such as olive, canola and sunflower oils in your diet, instead of saturated fats such as butter and lard that can increase risk of cardiovascular disease.

Water

Often ignored as a nutrient, water is vital for numerous functions in the body. It forms about 60 percent of the body weight and helps to maintain blood volume, blood pressure and body temperature. It lubricates joints, moisturizes tissues of the eyes, nose and mouth, enables nerve and muscle function and prevents constipation. Another important function of water is the transport of nutrients to the different cells and excretion of waste from the body. While the need for water varies with age, adults need about eight cups of water every day.

Vitamins

Of the 13 vitamins essential for health, nine are water-soluble and four are fat-soluble. Water-soluble B vitamins thiamin, riboflavin, niacin, folate, vitamin B-6, biotin, pantothenic acid and vitamin B-12 help release energy from food, prevent neural tube birth defects, are needed for DNA and RNA synthesis and play a role in development of the nervous system. Vitamin C acts as an antioxidant and helps build strong gums, teeth and bones. Fat-soluble vitamin A is necessary for vision, vitamin D helps build strong bones, vitamin

...