Food is any material eaten to supply body nutrition for an individual. The type of food and its nutritional value determine the individual’s health. Most food is of animal, plant or fungi origin, and generally contains necessary nutrients, including proteins, carbohydrates, vitamins, minerals or both. During human life, food plays a major role in providing energy and sustenance. Food is categorized into three categories: diet, main meals, and snacks. Diet involves the intake of food in large amounts; main meals are food groups eaten in the day; and snacks are food items eaten between meals.
Food can be classified into three types: carbohydrates, which include glucose and other sugars; proteins, which include the proteins of plants and animals; and vitamins, which include water-soluble and insoluble vitamins. Some food substances are usually combined with other food substances in the preparation of meals or snacks, and they change their nutritional value according to the mixture. Vitamins and minerals are food components that are not required to be consumed in their raw form, but are used as components of food in preparations to make them healthy. Some examples of vitamins include vitamin D, thiamin, pantothenic acid, folic acid, niacin, riboflavin, potassium, and magnesium.
The food consumption habits and the nutritional values of an individual determine his/her health status, and thus determine his/her potential for survival. In order to achieve optimal nutrition, people need to consume a well-balanced diet rich in complex carbohydrates and fiber along with healthy fats and proteins. Foods that are rich in calories also provide energy for the body, but these should be avoided, since calories may cause obesity and other health problems. For those who are unable to control their weight, controlled diet is often recommended by dietitians and other health care professionals.