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.

In a human epidemiological analysis by Richard Doll and Richard Peto in 1981, diet was estimated to cause a large percentage of cancers.[31] Studies suggest that around 32% of cancer deaths may be avoidable by changes to the diet.[32] Some of these cancers may be caused by carcinogens in food generated during the cooking process, although it is often difficult to identify the specific components in diet that serve to increase cancer risk. Many foods, such as beef steak and broccoli, contain low concentrations of both carcinogens and anticarcinogens.[33]

The process of making a diet version of a food usually requires finding an acceptable low-food-energy substitute for some high-food-energy ingredient.[16] 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 food energy. In other cases, low-fat ingredients may be used as replacements.


While some Christians consider the use of wine from the grape as essential for the validity of the sacrament, many Protestants also allow (or require) pasteurized grape juice as a substitute. Wine was used in Eucharistic rites by all Protestant groups until an alternative arose in the late 19th century. Methodist dentist and prohibitionist Thomas Bramwell Welch applied new pasteurization techniques to stop the natural fermentation process of grape juice. Some Christians who were part of the growing temperance movement pressed for a switch from wine to grape juice, and the substitution spread quickly over much of the United States, as well as to other countries to a lesser degree.[112] There remains an ongoing debate between some American Protestant denominations as to whether wine can and should be used for the Eucharist or allowed as an ordinary drink, with Catholics and some mainline Protestants allowing wine drinking in moderation, and some conservative Protestant groups opposing consumption of alcohol altogether.[citation needed]
Between the extremes of optimal health and death from starvation or malnutrition, there is an array of disease states that can be caused or alleviated by changes in diet. Deficiencies, excesses, and imbalances in diet can produce negative impacts on health, which may lead to various health problems such as scurvy, obesity, or osteoporosis, diabetes, cardiovascular diseases as well as psychological and behavioral problems. The science of nutrition attempts to understand how and why specific dietary aspects influence health.
Along with changes in food, starting early in the 20th century, governments have issued nutrition guidelines, leading to the food pyramid[13] (introduced in Sweden in 1974). The 1916 "Food For Young Children" became the first USDA guide to give specific dietary guidelines. Updated in the 1920s, these guides gave shopping suggestions for different-sized families along with a Depression Era revision which included four cost levels. In 1943, the USDA created the "Basic Seven" chart to make sure that people got the recommended nutrients. It included the first-ever Recommended Daily Allowances from the National Academy of Sciences. In 1956, the "Essentials of an Adequate Diet" brought recommendations which cut the number of groups that American school children would learn about down to four. In 1979, a guide called "Food" addressed the link between too much of certain foods and chronic diseases, but added "fats, oils, and sweets" to the four basic food groups.
This principle involves eating low-energy-dense foods and can help you lose weight by feeling full on fewer calories. Healthy choices in each of the other food groups in moderate amounts make up the rest of the pyramid — including whole-grain carbohydrates, lean sources of protein such as legumes, fish and low-fat dairy, and heart-healthy unsaturated fats.
Wine refrigerators offer a smaller alternative to wine cellars and are available in capacities ranging from small, 16-bottle units to furniture-quality pieces that can contain 400 bottles. Wine refrigerators are not ideal for aging, but rather serve to chill wine to the proper temperature for drinking. These refrigerators keep the humidity low (usually under 50%), below the optimal humidity of 50% to 70%. Lower humidity levels can dry out corks over time, allowing oxygen to enter the bottle, which reduces the wine's quality through oxidation.[142] While some types of alcohol are sometimes stored in freezer, such as vodka, it is not possible to safely freeze wine in the bottle, as there is insufficient room for it to expand as it freezes and the bottle will usually crack. Certain shapes of bottle may allow the cork to be pushed out by the ice, but if the bottle is frozen on its side, the wine in the narrower neck will invariably freeze first, preventing this.
For people who are healthy, a healthy diet is not complicated and contains mostly fruits, vegetables, and whole grains, and includes little to no processed food and sweetened beverages. The requirements for a healthy diet can be met from a variety of plant-based and animal-based foods, although a non-animal source of vitamin B12 is needed for those following a vegan diet.[29] 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.[30]
^ The sweetness multiplier "300 times" comes from subjective evaluations by a panel of test subjects Archived January 23, 2009, at the Wayback Machine tasting various dilutions compared to a standard dilution of sucrose. Sources referenced in this article say steviosides have up to 250 times the sweetness of sucrose, but others, including stevioside brands such as SweetLeaf, claim 300 times. 1/3 to 1/2 teaspoon (1.6–2.5 ml) of stevioside powder is claimed to have equivalent sweetening power to 1 cup (237 ml) of sugar.
Various food preservation and packaging techniques are used to extend a food's shelf life. Decreasing the amount of available water in a product, increasing its acidity, or irradiating[56] or otherwise sterilizing the food and then sealing it in an air-tight container are all ways of depriving bacteria of suitable conditions in which to thrive. All of these approaches can all extend a food's shelf life without unacceptably changing its taste or texture.

Communication between the Old World and the New World in the Columbian Exchange influenced the history of cooking. The movement of foods across the Atlantic, from the New World, such as potatoes, tomatoes, maize, beans, bell pepper, chili pepper, vanilla, pumpkin, cassava, avocado, peanut, pecan, cashew, pineapple, blueberry, sunflower, chocolate, gourds, and squash, had a profound effect on Old World cooking. The movement of foods across the Atlantic, from the Old World, such as cattle, sheep, pigs, wheat, oats, barley, rice, apples, pears, peas, chickpeas, green beans, mustard, and carrots, similarly changed New World cooking.[11]

Proponents of raw foodism argue that cooking food increases the risk of some of the detrimental effects on food or health. They point out that during cooking of vegetables and fruit containing vitamin C, the vitamin elutes into the cooking water and becomes degraded through oxidation. Peeling vegetables can also substantially reduce the vitamin C content, especially in the case of potatoes where most vitamin C is in the skin.[26] However, research has shown that in the specific case of carotenoids a greater proportion is absorbed from cooked vegetables than from raw vegetables.[17]
There are very many methods of cooking, most of which have been known since antiquity. These include baking, roasting, frying, grilling, barbecuing, smoking, boiling, steaming and braising. A more recent innovation is microwaving. Various methods use differing levels of heat and moisture and vary in cooking time. The method chosen greatly affects the end result because some foods are more appropriate to some methods than others. Some major hot cooking techniques include:
Fermentation of the non-colored grape pulp produces white wine. The grapes from which white wine is produced are typically green or yellow. Some varieties are well-known, such as the Chardonnay, Sauvignon, and Riesling. Other white wines are blended from multiple varieties; Tokay, Sherry, and Sauternes are examples of these. Dark-skinned grapes may be used to produce white wine if the wine-maker is careful not to let the skin stain the wort during the separation of the pulp-juice. Pinot noir, for example, is commonly used to produce champagne.
Edible animal material, including muscle, offal, milk, eggs and egg whites, contains substantial amounts of protein. Almost all vegetable matter (in particular legumes and seeds) also includes proteins, although generally in smaller amounts. Mushrooms have high protein content. Any of these may be sources of essential amino acids. When proteins are heated they become denatured (unfolded) and change texture. In many cases, this causes the structure of the material to become softer or more friable – meat becomes cooked and is more friable and less flexible. In some cases, proteins can form more rigid structures, such as the coagulation of albumen in egg whites. The formation of a relatively rigid but flexible matrix from egg white provides an important component in baking cakes, and also underpins many desserts based on meringue.
Various food preservation and packaging techniques are used to extend a food's shelf life. Decreasing the amount of available water in a product, increasing its acidity, or irradiating[56] or otherwise sterilizing the food and then sealing it in an air-tight container are all ways of depriving bacteria of suitable conditions in which to thrive. All of these approaches can all extend a food's shelf life without unacceptably changing its taste or texture.
Fruits are the ripened ovaries of plants, including the seeds within. Many plants and animals have coevolved such that the fruits of the former are an attractive food source to the latter, because animals that eat the fruits may excrete the seeds some distance away. Fruits, therefore, make up a significant part of the diets of most cultures. Some botanical fruits, such as tomatoes, pumpkins, and eggplants, are eaten as vegetables.[10] (For more information, see list of fruits.)
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