Digestion and Absorption

Digestion is the breakdown of food into smaller particles or individual nutrients. It is accomplished through six basic processes, with the help of several body fluids—particularly digestive juices that are made up of compounds such as saliva, mucus, enzymes, hydrochloric acid, bicarbonate, and bile.

The six processes of digestion involve: (1) the movement of food and liquids; (2)…

Dietitian

A dietitian is a professional nutritionist—an educated food and nutrition  specialist who is qualified by training and examination to evaluate people’s nutritional health and needs. Most dietitians are registered and are referred to as RDs. To become an RD, a person must earn an undergraduate degree in nutrition, food science, or food management, including courses in several other related…

Dietary Trends, International

What foods an individual eats is affected by the ability to access foods. Economic status, geography, and politics have influenced the diets of people throughout history. Poverty is linked to malnutrition, while economic growth and a rise in population pose new nutritional problems. Ironically, diets high in complex carbohydrates and fiber in poor economic times give way…

Dietary Trends, American

Americans have become more aware of what they eat, and how it might affect their health. Concerns about the safety of the food supply are on the rise, and increasing nutritional awareness has led to an increase in vegetarian, organic, and health-food options in supermarkets. “Lite” food is in, and indulgence is out. But are Americans practicing what they…

Dietary Supplements

Definition

In the United States, dietary supplements are defined by the 1994 Dietary Supplement Health and Education Act as products that are not used exclusively as food, but are intended to be consumed in addition to an individual’s diet. The law states that dietary supplements are taken by mouth and contain.

one or more dietary ingredients. Examples of dietary ingredients include…

Dietary Reference Intakes

Definition

Dietary reference intakes (DRI) are a set of reference values for vitamins, minerals, and other nutrients important to human health. DRIs provide guidance about the appropriate amount of each nutrient that should be consumed based on American and Canadian diets. DRIs are specific to age group, gender, and for women, reproductive status. Purpose

DRIs are tools intended to be…

Dietary Guidelines

Description Early Dietary Advice in the United States

The first half of the twentieth century was a period of enormous growth in nutrition knowledge. The primary goal of nutrition advice at this time was to help people select foods to meet their energy (calorie) needs and prevent nutritional deficiencies. During the Great Depression of the 1930s, food was rationed and people…

Diabetes Mellitus

Definition

Diabetes mellitus is a condition in which the pancreas no longer produces enough insulin or cells stop responding to the insulin that is produced, so that glucose in the blood cannot be absorbed into the cells of the body. Symptoms include frequent urination, lethargy, excessive thirst, and hunger. The treatment includes changes in diet, oral medications, and in…

Cravings

Definition

Most people, at some time, have a strong desire for some particular food, such as ice cream or pizza. Such a desire for a particular food, even when one is not hungry, is called a craving. Description

There are a number of theories as to why people crave certain foods, including:

* self-imposed food restriction * a psychological desire for a “comfort” food *…

Corn or Maize-Based Diets

Maize, the American Indian word for corn, literally means “that which sustains life.” After wheat and rice, it is the most important cereal grain in the world, providing nutrients  for humans and animals. It also serves as a basic raw material for the production of starch, oil, protein, alcoholic beverages, food sweeteners, and fuel. Maize has…

Commodity Foods

The United States Department of Agriculture (USDA) administers several programs that distribute commodity foods, which are foods that the federal government has the legal authority to purchase and distribute in order to support farm prices. The first commodity distribution program began during the Great Depression of the 1930s, when it was known as the Needy Family Program. This…