In nutrition, diet is the sum of food consumed by a person or other organism. The word diet often implies the use of specific intake of nutrition for health or weight-management reasons. 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, and 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. Exclusionary diets are diets with certain groups or specific types of food avoided, either due to health considerations or by choice. Many do not eat food from animal sources to varying degrees 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. People on a balanced vegetarian and vegan diet can get all necessary nutrients, but may need to specifically focus on consumption of nutrients like protein, iron, calcium, zinc, and vitamin B12.

Raw foodism and intuitive eating are other approaches to dietary choices. Education, income, local availability, and mental health are all major factors for dietary choices. A particular diet may be chosen to promote weight loss or weight gain. Changing a person'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.

The terms "healthy diet" and "diet for weight management" are often related, as the two promote healthy weight management. If a person is overweight or obese, changing to a diet and lifestyle that allows them to burn more calories than they consume may improve their overall health, possibly preventing diseases that are attributed in part to weight, including heart disease and diabetes. Within the past 10 years, obesity rates have increased by almost 10%. Conversely, if a person is underweight due to illness or malnutrition, they may change their diet to promote weight gain. Intentional changes in weight, though often beneficial, can be potentially harmful to the body if they occur too rapidly. Unintentional rapid weight change can be caused by the body's reaction to some medications, or may be a sign of major medical problems including thyroid issues and cancer among other diseases. An eating disorder is a mental disorder that interferes with normal food consumption. It is defined by abnormal eating habits and thoughts about food that may involve eating much more or much less than needed.

Common eating disorders include anorexia nervosa, bulimia nervosa, and binge-eating disorder. A healthy diet may contain fruits, vegetables, and whole grains, and may include little to no processed food or sweetened beverages. The requirements for a healthy diet can be met from a variety of plant-based and animal-based foods, although a non-plant source of vitamin B12 is needed for those following a vegan diet. Various nutrition guides are published by medical and governmental institutions to educate individuals on what they should be eating to be healthy. Nutrition facts labels are also mandatory in some countries to allow consumers to choose between foods based on the components relevant to health.

Regards

Managing Editor

Damon Wilson

Journal of Nutrition & Food Sciences