Diets

In nutrition, the diet is the sum of the food consumed by a person or other organism. Dietary habits are the habitual decisions an individual or culture makes when choosing what foods to eat.

Although humans are omnivores, each culture holds some food preferences and some food taboos. Individual dietary choices may be more or less healthy. Proper nutrition requires vitamins, minerals, and fuel in the form of carbohydrates, proteins, and fats. Dietary habits play a significant role in the health and mortality of all humans. Dietary choices can also define cultures and play a role in religion.

Cultural dietary choices
Some cultures and religions have restrictions concerning what foods are acceptable in a diet. For example, only Kosher foods are permitted by Judaism, and Halal/Haram foods by Islam, in the diet of believers. In addition, the dietary choices of different countries or regions have different characteristics. For instance, Americans eat more red meat than people in most other countries, and Japanese eat more fish and rice. Rice and beans are typical parts of a diet in Latin-American countries, while lentils and pita bread are typical in the Middle East. This is highly related to a culture's cuisine.

Concerns about foodborne illness have long influenced diet. Traditionally humans have learned to avoid foods that induce acute illness. Some believe that this is the underlying rationale behind some traditional religious dietary requirements.

Individual dietary choices
Many individuals choose to limit what foods they eat for reasons of health, morality, or other factors. Additionally, many people choose to forgo food from animal sources to varying degrees; see vegetarianism, veganism, fruitarianism, living foods diet, and raw foodism.

The nutrient content of diets in industrialised countries contain more animal fat, sugar, energy, alcohol and less dietary fiber, carbohydrates and antioxidants. Contemporary changes to work, family and exercise patterns, together with concerns about the effect of nutrition and overeating on human health and mortality are all having an effect on traditional eating habits. Physicians and alternative medicine practitioners may recommend changes to diet as part of their recommendations for treatment.

More recently, dietary habits have been influenced by the concerns that some people have about possible impacts on health or the environment from genetically modified food. Further concerns about the impact of industrial farming on animal welfare, human health and the environment are also having an effect on contemporary human dietary habits. This has led to the emergence of a counterculture with a preference for organic and local food.

Diets for weight management
A particular diet may be chosen to seek weight gain, weight loss, sports training, cardio-vascular health, avoidance of cancers, food allergies and for other reasons. 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. Foods intended to help produce weight loss are frequently labeled "diet foods". These diets are often recommended in conjuction with exercise.

Dietary health
Imbalances between the consumed fuels and expended energy results in either starvation or excessive reserves of adipose tissue, known as body fat. Poor intake of various vitamins and minerals can lead to diseases which can have far-reaching effects on health. For instance, 30% of the world's population either has, or is at risk for developing, Iodine deficiency. It is estimated that at least 3 million children are blind due to vitamin A deficiency. Vitamin C deficiency results in scurvy. Calcium, Vitamin D and Phosphorus are inter-related; the consumption of each may affect the absorption of the others. Kwashiorkor and marasmus are childhood disorders caused by lack of dietary protein. Obesity, a serious problem in the western world, leads to higher chances of developing heart disease, diabetes, and many other diseases.

Eating disorders are a group of mental disorders that interfere with normal food consumption. They often affect people with a negative body image.