Human nutrition fundamentals and applications

Human Nutrition

Carbohydrates are the key source of energy of the human body, which uses them to produce sugar glucose to help maintain tissue protein, metabolize fat and fuel the nervous system (MSN Encarta 2006). The major carbohydrates are starches and sugars. Examples of common starches are whole-grain breads and cereals, pasta, corn, beans, peas and potatoes. Natural sources of sugar include fruits and many vegetables, milk products, honey, maple sugar and sugar cane (MSN Encarta).

Dietary proteins are compounds, which build and repair body tissues, speed up chemical reactions in the body, serve as chemical messengers, fight infection and bring oxygen from the lungs to the body tissues (MSN Encarta 2006). Excellent sources of animal proteins include eggs, milk, meat, fish and poultry. Examples of plant sources are vegetables, grains and beans (MSN Encarta).

Fats are the most concentrated energy-producing nutrients, which play a significant role in building the membranes surrounding body cells and in forming blood clots (MSN Encarta 2006). Fats also help the body absorb certain vitamins, cushion vital organs and protect the body from extreme cold and heat. Examples of sources of animal fats are eggs, dairy products and meats. Examples of vegetable fats include avocados, olives, some nuts and vegetable oils (MSN Encarta).

Vitamins enhance the body's use of carbohydrates, proteins and fats; help in forming blood cells, hormones, neurotransmitters and the genetic material called DNA; and prevent many health disorders (MSN Encarta 2006). Minerals are metallic elements required for the healthy growth of teeth and bones and in other cellular functions. Excellent food sources of vitamins and minerals include oranges, milk, and sweet potatoes (MSN Encarta).