Food is any material consumed to supply nutrition to the organisms. Food consists of any material of plant, animal, or fungus origin, and has vital nutrients, including vitamins, minerals, proteins, carbohydrates, and fats. In modern human beings food habits have changed over time, with a tendency towards increased consumption of meat and dairy products, especially red meat. This has had a marked effect on the type and quantity of the various nutrients contained in food. This article discusses the effects of food on nutrition and the food sources and limitations.
The main dietary fiber consumed by humans is found in cereal grains, which are refined or processed foods containing high levels of starches, such as potatoes and rice; certain fruits, including most bananas; legumes, beans, and nuts; and cereals. Most of the carbohydrate intake is derived from these foods. Almost all food-eating animals feed on a diet of animal flesh, including fish and poultry. Plants have relatively low carbohydrate content, although they may contain some carbohydrates. The main source of carbohydrates in plant foods is starch, found in roots, leafy vegetables, and whole grains.
Food provides different nutrients in different proportions and amounts. There are three major categories, including whole foods, which include fresh fruits and vegetables, whole grains, and dairy products; whole food supplements, which consist mainly of vitamins and mineral salts; and processed food, which include sugar, salt, artificial flavorings, and saturated fat. The composition of the food eaten depends largely on the source, and the amount consumed and the time since the food has been consumed. It is recommended that all individuals should be sure to get their daily allowances of nutrients from foods that are appropriate for their individual size and activity level. For children, the recommended diet is based on a variety of studies and a few assumptions about typical eating patterns of children in their communities.
The basic food groups are protein, vegetable protein, carbohydrates, fat, minerals and vitamins. The four major food categories each contain a variety of nutrient sources and each has specific functions that optimize its use. Protein is the most important of all nutrient sources and it is the foundation of all muscle-building and building tissue. Meat, fish, poultry, and eggs are some of the best sources of protein.
Vegetable and grain protein are considered the most complete food groups and provide the greatest amount of nutrients. The vegetable protein (such as soy protein) is considered the healthiest food because it contains the most nutrients. Whole grains such as whole wheat bread and pasta are good choices for nutrition, though high in calories and fat. Frozen vegetables are always good choices, though high in sodium and fats.
In a healthy balanced diet, all of the major food groups should be eaten in moderation and some foods may be avoided. Nuts, beans, potatoes, and whole grains should be eaten in moderation and should not be substituted for vegetables, fruits, meats, or protein. Oils and fats may also be avoided, especially saturated fats. In addition, some dairy products, fish, beans, mushrooms, poultry, meats, and eggs may also be avoided.