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Royal Academy of Nutrition and Health Eating

1. Themes


What Is Nutrition?

What Drives Our Food Choices?

We Need to Eat and Drink to Live

We Choose Foods for Many Other Reasons

What Is Nutrition and Why Is Good Nutrition So Important?

What Are the Essential Nutrients and Why Do You Need Them?

Carbohydrates, Fats, and Proteins Provide Energy

Vitamins and Minerals Are Essential for Metabolism

Water Is Vital for Many Processes in Your Body

How Should You Get These Important Nutrients?

The Best Way to Meet Your Nutrient Needs Is with a Well-Balanced Diet

You Can Meet Some Nutrient Needs with a Supplement

How Does the Average American Diet Stack Up?

The Quality of the American Diet

Rates of Overweight and Obesity in Americans

Improving Americans' Diets Is One Goal of Healthy People 2020

 What's the Real Deal When It Comes to Nutrition Research and Advice?

Sound Nutrition Research Begins with the Scientific Method

Research Studies and Experiments Confirm Hypotheses

You Can Trust the Advice of Nutrition Experts

You Can Obtain Accurate Nutrition Information on the Internet

Tools for Healthy Eating

The Basics of Digestion

Carbohydrates: Sugars, Starches, and Fiber

Fats, Oils, and Other Lipids

Proteins and Amino Acids


Minerals and Water


Weight Management and Energy Balance

Nutrition and Fitness

Consumerism: From Farm to Table

Food Safety and Technology

Hunger at Home and Abroad

Life Cycle Nutrition: Pregnancy through Infancy

Life Cycle Nutrition: Toddlers through the Later Years



2. Introduction

Need to freshen up your knowledge of nutrition? Or, do you need to get up to speed on basic nutrition for the course? This course presents information about nutrition that paves the way to greater understanding of specific needs and benefits related to nutrition by life-cycle stage.

Nutrition is an interdisciplinary science focused on the study of foods, nutrients, and other food constituents and health. The body of knowledge about nutrition is large and is growing rapidly, changing views on what constitutes the best nutrition advice.

You are encouraged to refer to nutrition texts and to use the online resources listed later on to fill in any knowledge gaps.

You are also encouraged to stay informed in the future and to keep an open mind about the best nutrition advice for many health-related issues.

Scientific evidence that drives decisions about nutrition and health changes with time.

The first part of our course centers on:

(1) The principles of the science of nutrition;

(2) Nutrients and other constituents of food;

(3) Nutritional assessment;

(4) Public food and nutrition programs, and

(5) Priorities for improvements in the public's nutritional health.

1. Nutrition is the study of foods, their nutrients and other chemical constituents, and the effects of food constituents on health.

2. Nutrition is an interdisciplinary science.

3. Nutrition recommendations for the public change as new knowledge about nutrition and health relationships is gained.

4. At the core of the science of nutrition are principles that represent basic truths and serve as the foundation of our understanding about nutrition.

5. Healthy individuals require the same nutrients across the life cycle but in differing amounts. Nutritional needs can be met by a wide variety of cultural and religious food practices.

6. Nutritional status during one stage of the life cycle influences health status during subsequent life-cycle stage.


3. Principles of the Science of Nutrition

Every field of science is governed by a set of principles that provides the foundation for growth in knowledge.

These principles change little with time.

Knowledge of the principles of nutrition listed bellow will serve as a springboard to greater understanding of the nutrition and health relationships explored later on.

PRINCIPLE #1- Food is a basic need of humans.

Humans need enough food to live and the right assortment of foods for optimal health People who have enough food to meet their needs at all times experience food security. They are able to acquire food in socially acceptable ways - without having to scavenge or steal food.

Food insecurity exists when the availability of safe, nutritious foods, or the ability to acquire them in socially acceptable ways, is limited or uncertain. About 12% of U.S. households are food insecure.

PRINCIPLE #2 - Foods provide energy (calories), nutrients, and other substances needed for growth and health.

People eat foods for many different reasons. The most compelling reason is the requirement for calories (energy), nutrients, and other substances supplied by foods for growth and health.


4. Principles of human nutrition

Principle #1- Food is a basic need of humans.

Principle #2 - Foods provide energy (calories), nutrients, and other substances needed for growth and health.

Principle #3 - Health problems related to nutrition originate within cells.

Principle #4 - Poor nutrition can result from both inadequate and excessive levels of nutrient intake.

Principle #5 - Humans have adaptive mechanisms for managing fluctuations in food intake.

Principle #6 - Malnutrition can result from poor diets and from disease states, genetic factors, or combinations of these causes.

Principle #7- Some groups of people are at higher risk of becoming inadequately nourished than others.

Principle #8 - Poor nutrition can influence the development of certain chronic diseases.

Principle #9 - Adequacy, variety, and balance are key characteristics of a healthy diet.

Principle #10 - There are no "good" or "bad" foods.

Nutrients - Chemical substances in foods that are used by the body for growth and health.

Food Security Access at all times to a sufficient supply of safe, nutritious foods.

Food Insecurity Limited or uncertain availability of safe, nutritious foods, or the ability to acquire them in socially acceptable ways.

Calorie - A unit of measure of the amount of energy supplied by food. Also known as the "kilocalorie" (kcal), or the "large Calorie."

A calorie is a measure of the amount of energy transferred from food to the body.

Because calories are a unit of measure and not a substance actually present in food, they are not considered to be nutrients.

Nutrients are chemical substances in food that the body uses for a variety of functions that support growth, tissue maintenance and repair, and ongoing health.

Essentially, every part of our body was once a nutrient consumed in food.

There are six categories of nutrients. Each category except water consists of a number of different substances.


5. Nutrients

Of the many nutrients required for growth and health, some must be provided by the diet while others can be made by the body.

1) Essential Nutrients - Nutrients the body cannot manufacture, or generally produce in sufficient amounts, are referred to as essential nutrients. Here essential means "required in the diet."

All of the following nutrients are considered essential:

  • Carbohydrates
  • Certain amino acids (the essential amino acids: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine)
  • Linoleic acid and alpha-linolenic acid (essential fatty acids)
  • Vitamins
  • Minerals
  • Water

2) Nonessential Nutrients

Cholesterol, creatine, and glucose are examples of nonessential nutrients.

Nonessential nutrients are present in food and used by the body, but they do not have to be part of our diets. Many of the beneficial chemical substances in plants are not considered essential, for example, yet they play important roles in maintaining health.

 Essential Nutrients Substances required for growth and health that cannot be produced, or produced in sufficient amounts, by the body. They must be obtained from the diet.

Essential Amino Acids Amino acids that cannot be synthesized in adequate amounts by humans and therefore must be obtained from the diet. Also called "indispensible amino acids."

Nutrients required for growth and health that can be produced by the body from other components of the diet.

3) Requirements for Essential Nutrients

All humans require the same set of essential nutrients, but the amount of nutrients needed varies based on:

  • Age
  • Illness
  • Body size
  • Lifestyle habits (e.g., smoking, alcohol intake)
  • Gender
  • Genetic traits
  • Medication use
  • Growth
  • Pregnancy and lactation

Amounts of essential nutrients required each day vary a great deal, from cups (for water) to micrograms (for example, for foliate and vitamin B12).



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