In nutrition, the diet is the sum of the food consumed by an organism. Proper nutrition for a human requires vitamins, minerals, proteins, and fuel in the form of carbohydrates and fats. Imbalances between the consumed fuels and expended energy results in either starvation or excessive reserves of adipose tissue, or body fat. Poor intake of various vitamins and minerals can lead to diseases like scurvy or iodine deficiency.
A particular diet may be chosen to seek weight gain, weight loss, sports training, cario-vascular health, avoidance of cancers, food allergies and for other reasons. Changing the subject's dietary intake or going on a diet can change the energy balance and increase or decrease the amount of fat stored by the body. Some foods are specifically recommended, or even altered, for conformity to the requirements of a particular diet. Foods intended to help produce weight loss are frequently labeled "diet foods".