In nutrition, diet is the sum of food consumed by a person or other organism.[1] The word diet often implies the use of specific intake of nutrition for health or weight-management reasons (with the two often being related). Although humans are omnivores, each culture and each person holds some food preferences or some food taboos. This may be due to personal tastes or ethical reasons. Individual dietary choices may be more or less healthy.

Complete nutrition requires ingestion and absorption of vitamins, minerals, essential amino acids from protein and essential fatty acids from fat-containing food, also food energy in the form of carbohydrate, protein, and fat. Dietary habits and choices play a significant role in the quality of life, health and longevity.

Religious and cultural dietary choices

Some cultures and religions have restrictions concerning what foods are acceptable in their diet. For example, only Kosher foods are permitted by Judaism, and Halal foods by Islam. Although Buddhists are generally vegetarians, the practice varies and meat-eating may be permitted depending on the sects.[2] In Hinduism, vegetarianism is the ideal. Jains are strictly vegetarian and consumption of roots is not permitted.

Dietary choices

Many people choose to forgo food from animal sources to varying degrees (e.g. flexitarianism, vegetarianism, veganism, fruitarianism) for health reasons, issues surrounding morality, or to reduce their personal impact on the environment, although some of the public assumptions about which diets have lower impacts are known to be incorrect.[3] Raw foodism is another contemporary trend. These diets may require tuning or supplementation such as vitamins to meet ordinary nutritional needs.

Weight management

A particular diet may be chosen to seek weight loss or weight gain. Changing a 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. These diets are often recommended in conjunction with exercise. Specific weight loss programs can be harmful to health, while others may be beneficial and can thus be coined as healthy diets. The terms "healthy diet" and "diet for weight management" are often related, as the two promote healthy weight management. Having a healthy diet is a way to prevent health problems, and will provide the body with the right balance of vitamins, minerals, and other nutrients.[4]

Eating disorders

An eating disorder is a mental disorder that interferes with normal food consumption. It is defined by abnormal eating habits that may involve either insufficient or excessive diet.


A healthy diet may improve or maintain optimal health. In developed countries, affluence enables unconstrained caloric intake and possibly inappropriate food choices.[5]

Health agencies recommend that people maintain a normal weight by limiting consumption of energy-dense foods and sugary drinks, eating plant-based food, limiting consumption of red and processed meat, and limiting alcohol intake.[6]

Diet classification table

Food Type Carnivorous Ketogenic Omnivorous Pescetarian Vegetarian Vegan Jewish Islamic Hindu Paleolithic Fruitarian
Fruits and berries No No Yes Yes Yes Yes Yes Yes Yes Yes Yes
Greens No Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
Vegetables No Yes Yes Yes Yes Yes Yes Yes Yes Yes No[a]
Legumes No No Yes Yes Yes Yes Yes Yes Yes No Maybe
Nuts No Yes Yes Yes Yes Yes Yes Yes Yes Yes Maybe
Tubers No No Yes Yes Yes Yes Yes Yes Yes Yes No
Grains No No Yes Yes Yes Yes Yes Yes Yes No Maybe
Beef Yes Yes Yes No No No Yes Yes No Yes No
Pork Yes Yes Yes No No No No No Maybe Yes No
Poultry Yes Yes Yes No No No Yes Yes Maybe Yes No
Fish (scaled) Yes Yes Yes Yes No No Yes Yes Maybe Yes No
Seafood (non-fish) Yes Yes Yes Yes No[b] No[b] No Yes Maybe Yes No
Insects Yes Maybe Yes No No No No[c] No[c] Maybe Yes No
Eggs Yes Yes Yes Yes Maybe[d] No Yes Yes Yes Yes No
Dairy No Yes[e] Yes Yes Maybe No Yes Yes Yes No No
Alcohol No Maybe Yes Yes Yes Yes Yes No Yes No No


  1. ^ Some plants traditionally considered to be vegetables—such as tomatoes, eggplants, capsicums, and zucchinis—are permitted.
  2. ^ a b Plant seafood, such as seaweeds and microphytes, is permitted.
  3. ^ a b Locusts are sometimes permitted, depending on the religious denomination.
  4. ^ Both ovo vegetarians and ovo-lacto vegetarians permit eggs.
  5. ^ Both lacto vegetarians and ovo-lacto vegetarians permit dairy.


  1. ^ noun, def 1 – askoxford.com
  2. ^ Keown, Damien (26 August 2004). A Dictionary of Buddhism. Oxford University Press. p. 77. ISBN 9780191579172. 
  3. ^ The embodied energy of food: the role of diet DA Coley, E Goodliffe, J Macdiarmid Energy Policy 26 (6), 455-460
  4. ^ "Healthy Eating: How do you get started on healthy eating?". Webmd.com. 2009-10-12. Retrieved 2011-12-11. 
  5. ^ "Told to Eat Its Vegetables, America Orders Fries" article by Kim Severson in The New York Times September 24, 2010, accessed September 25, 2010
  6. ^ "Policy and Action for Cancer Prevention Food, Nutrition, and Physical Activity" (PDF). World Cancer Research Fund & American Institute for Cancer Research. 2010. 

See also

External links

  • The dictionary definition of diet at Wiktionary