Plate with green salad, onion, tomato, cucumber, carrot and a black olive

In nutrition, diet is the sum of food that is eaten by a person or another organism.Dietary habits are the usual decisions someone or a culture makes when choosing what foods to eat.

In discussing diet, the key issue is the change in work done. People have moved from manual work to office-type work, and to houses which have washing machines (et cetera). This has happened usually without changes in eating habits got during childhood. This is the basic reason why people get fat, with all the problems which follow.