Diet food (or dietetic food) refers to any food or drink whose recipe has been altered in some way to make it part of a body modification diet. Although the usual intention is weight loss and change in body type, sometimes the intention is to aid in gaining weight or muscle as in bodybuilding supplements.

Terminology

In addition to diet other words or phrases are used to identify and describe these foods including light or lite, low calorie, low fat, no fat, fat free, no sugar, sugar free, and zero calorie. In some areas use of these terms may be regulated by law. For example in the U.S. a product labeled low fat must not contain more than 3 grams of fat per serving; and to be labeled fat free it must contain less than 0.5 grams of fat per serving.

Process

The process of making a diet version of a food usually requires finding an acceptable low calorie substitute for some high calorie ingredient. This can be as simple as replacing some or all of the food's sugar with a sugar substitute as is common with diet soft drinks such as Coca-Cola (for example Diet Coke). In some snacks, the food may be baked instead of fried thus reducing the calories. In other cases, low fat ingredients may be used as replacements.

In whole grain foods, the higher fiber content effectively displaces some of the starch component of the flour. Since certain fibers have no calories, this results in a modest caloric reduction. Another technique relies on the intentional addition of other reduced-calorie ingredients, such as resistant starch or dietary fiber, to replace part of the flour and achieve a more significant caloric reduction.