Metabolism refers to the physical and chemical processes that occur inside the cells of the body and that maintain life. Metabolism consists of anabolism (the constructive phase) and catabolism (the destructive phase, in which complex materials are broken down).


Minerals are inorganic elements that originate in the earth and cannot be made in the body. They play important roles in various bodily functions and are necessary to sustain life and maintain optimal health, and thus are essential nutrients.

Mood-Food Relationships

Research on the connection between a person's mood and the food he or she eats has reveled what many people have long believed, that eating a certain food can influence a person's mood—at least temporarily. Research by Judith Wurtman, a professor at the Massachusetts Institute of Technology (MIT), has focused on how certain foods alter one's mood by influencing the level of certain brain chemicals called neurotransmitters.

National Academy of Sciences (NAS)

The National Academy of Sciences is a private agency that advises the federal government on scientific and technical matters. It is part of the National Academy, which also includes the National Academy of Engineering, the Institute of Medicine, and the National Research Council.

National Health and Nutrition Examination Survey (NHANES)

In the year 1999, 64 percent of the U.S. population was overweight or obese, while the prevalence of obesity among children and adolescents more than doubled during the previous two decades.

National Institutes of Health (NIH)

The U.S. National Institutes of Health (NIH) are charged with the vital mission of uncovering new knowledge that will lead to better health for everyone.

Native Americans, Diet of

When Christopher Columbus dropped anchor on the shores of San Salvador in the Caribbean Sea, he believed he reached India. Because he believed he was in India, Columbus named the inhabitants Indians, a term that was soon used to refer to all the native inhabitants of North America.

Nongovernmental Organizations

The term nongovernmental organization (NGO) gained widespread use beginning in 1945, when it was used in the United Nations Charter to clearly distinguish between governmental and private organizations. To be considered an NGO, an organization must be free from government control, non-profit, not considered a political party, and not involved in criminal activity.

Northern Europeans, Diet of

The countries of northern Europe include the United Kingdom of Great Britain (England, Scotland, Wales, Northern Ireland), the Republic of Ireland (now a sovereign country), and France. (Although southern France is generally considered to be part of southern Europe, it will be included in this discussion.) These countries are all part of the European Union.

Nutrient Density

Nutrient density is a measure of the nutrients a food provides compared to the calories it provides. Foods low in calories and high in nutrients are nutrient dense, while foods high in calories and low in nutrients are nutrient poor.

Nutrient-Drug Interactions

Medications have become an integral part of life for many people. Medicine serves to help people when they are sick, allowing them to live longer and healthier lives.


An important aspect of nutrition is the daily intake of nutrients. Nutrients consist of various chemical substances in the food that makes up each person's diet.


Nutrition is the science that studies the interactions between living organisms and food. Human nutrition includes the study of nutrients and other substances found in foods; how the human body uses nutrients for growth and maintenance; and the relationship between foods, food components, dietary patterns, and health.

Nutrition Education

Nutrition education is a critical component of most major health promotion and disease prevention programs. Research indicates that behavioral change is directly related to the amount of nutrition education received.

Nutrition Programs in the Community

In the United States, as in most developed countries, a number of services and programs exist to help those who are in need due to age, illness, poverty or adverse circumstances. This is often not the case in less-developed countries, where individuals and communities experience hardships due to a lack of social, health, and welfare services.

Nutritional Assessment

A nutrition assessment is an in-depth evaluation of both objective and subjective data related to an individual's food and nutrient intake, lifestyle, and medical history.

Nutritional Deficiency

Nutritional deficiencies occur when a person's nutrient intake consistently falls below the recommended requirement. Nutritional deficiencies can lead Children between 10–19 years of age face serious nutritional deficiencies worldwide, according to the World Health Organization.


Nutritionists are individuals who have studied the science of nutrition. Many nutritionists have a master's or doctoral degree in nutrition science and conduct research on food safety, eating habits, or the impact of food and nutrition on health.


Obesity, defined as a body mass index of 30 or greater, is an epidemic in the United States and other industrialized nations, and it is rapidly becoming one in developing nations. As countries transition to westernized lifestyles, obesity tends to increase.