Restriction of one's diet, for health, cultural or humanitarian reasons, to foods of fruit and vegetable origin. Most vegetarians, while excluding meat and fish from their diets, include foods of animal origin, such as milk, cheese, eggs, and butter. Such a diet should supply an adequate balance of nutrients and may protect against those chronic diseases related to consumption of excess animal fat. People with special dietary requirements – such as pregnant or feeding mothers, and very strict vegetarians – may require dietary supplements (see APPENDIX 5: VITAMINS).