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.
The word diet first appeared in English in the 13th century. Its original meaning was the same as in modern English, “habitually taken food and drink.” But diet was used in another sense too in the Middle and early modern English periods to mean “way of living.” This is, in fact, the original meaning of diet’s Greek ancestor diaita, which is derived from the verb diaitasthan, meaning “to lead one’s life.” In Greek, diaita, had already come to be used more specifically for a way of living prescribed by a physician, a diet, or other regimen.
Lose It! This two-week phase is designed to jump-start your weight loss, so you may lose up to 6 to 10 pounds (2.7 to 4.5 kilograms) in a safe and healthy way. In this phase, you focus on lifestyle habits that are associated with weight. You learn how to add five healthy habits, break five unhealthy habits and adopt another five bonus healthy habits. This phase can help you see some quick results — a psychological boost — and start practicing important habits that you'll carry into the next phase of the diet.
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]
Most food has its origin in plants. Some food is obtained directly from plants; but even animals that are used as food sources are raised by feeding them food derived from plants. Cereal grain is a staple food that provides more food energy worldwide than any other type of crop.[2] Corn (maize), wheat, and rice – in all of their varieties – account for 87% of all grain production worldwide.[3][4][5] Most of the grain that is produced worldwide is fed to livestock.
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