Food is any material consumed by an animal, to provide nutrition to an animal. Most commonly food is of animal, plant or fungi origin, and has necessary nutrients, including protein, vitamins, carbohydrates, fat, or minerals, which the body needs to perform normal body functions. The term “food” can also include the residues left on food after it is eaten, as in leftover food in a refrigerator, or in fertilizers, pesticides, antibiotics, and other drugs that the human body needs to survive.
The human body requires the appropriate balance of nutrients in order to function normally, and there are several factors which contribute to this requirement. A diet rich in fresh fruits and vegetables, with the appropriate levels of dietary fibre, minerals and vitamins provides the optimum nutrition. Specific nutrients which are particularly important in maintaining health and are found in a number of foods include fatty acids, amino acids, vitamin B-complex, mineral ions, probiotics, enzymes, hormones, carbohydrates, fiber, and potassium. Animal products contain a large amount of these nutrients and are therefore extremely important in a healthy diet. However, plant-based foods are rich in most of these nutrients but are often deficient in one or more of the above-mentioned essential elements.
Animal foods contain a wide range of nutrients which are essential to human life. For example, while a single serving of potato has only 4% of the daily recommended amounts of iron, a whole wheat bagel has almost twice that amount, along with B vitamins, selenium, zinc, magnesium, copper, and vitamin E. In contrast, plant-based foods are typically lacking in most of these nutrients, and many plants depend on animal foods to provide some or all of these nutrients. Some plants can actually be poisonous to animals, while other foods such as garlic and onions, while poisonous to man, may actually be harmless to animals if eaten in small quantities. Because humans and many animals are designed to eat a variety of different foods, it is important to avoid the common pitfalls that occur when eating too much food and eating too often.