What are proteins, fats, and carbohydrates? What is a calorie? How is good nutrition like a balancing act?

Diet and Nutrition
What is the nutritional value of different foods?
David gets some nutritional advice to help answer every mother's question, "Are you eating right, Honey?"
Segment length: 6:50


"You are what you eat." There's a lot of truth to this old cliché. What we eat and how much plays a big role in how healthy we feel. Culture also plays a role in how we feel about our bodies. Although healthy bodies come in a variety of shapes, many Americans hold ideal body images few can match. Teenagers are particularly susceptible to the myth of the perfect body, e.g., a thin body, or a muscle-bound physique.

For many teenagers, this is the time of rapid growth, yet the rate of eating disorders such as anorexia nervosa and bulimia for this age group have increased at alarming rates. Understanding basic nutrition and accepting our individual bodies are critical steps to good health.

Carbohydrates, fats, proteins, vitamins, and minerals are the basic nutritional building blocks that provide the fuel our bodies need to function and perform. Carbohydrates, such as breads, cereals, and sugar, are our main source of quick energy. Fats, whether solid or liquid, are our primary slow-burning energy sources. Proteins, both complete and incomplete, are the body's chief building materials. Essential vitamins and minerals are also found in many of the foods we eat.

Obtaining the right proportion of nutrients is critical to our health. Eating the right number of calories is just as important. Ideally, our caloric intake should equal the total amount of energy our bodies need for growth and repair. Using a calorimeter, nutritionists have calculated the caloric energy of particular foods. This information, and the product's ingredients, are listed on most food packages.

Keeping your body healthy is a personal balancing act. The goal is to get the essential nutrients you need, while eating no more calories than your body expends.


1. What influences you the most in what you eat? Friends? Television? Family patterns? Societal ideals?
2. How might the diets of your grandparents or great-grandparents differ from yours? Whose diet do you think is/was healthier?


anorexia nervosa an eating disorder involving a psychological loss of appetite, often resulting in self-starvation
bulimia an eating disorder involving binging and purging of food
calorie the amount of heat needed to raise the temperature of a kilogram of water 1deg.C
calorimeter an instrument that measures the energy found in food; a closed box containing a kilogram of water, an instrument to burn food, and a thermometer
carbohydrates sugars and starches made mostly by plants and used by the body as primary sources of quick-energy food
fats a group of nutrients found in solid and liquid form that is used as food or stored in the body as a slow-burning energy source
minerals 20 known nutrients that are found in trace amounts; include magnesium, phosphorus, potassium, sodium, and sulfur
proteins chief building material of the body, manufacturing muscles, bones, hair, and more; comprised of a variety of amino acids, all of which contain carbon, nitrogen, oxygen, and hydrogen
vitamins essential nutrients that are needed to sustain life; 13 vitamins have been identified: A, C, D, E, K, and eight parts of vitamin B


Franz, M.J. (1990) Fast food facts: Nutritive and exchange values for fast-food restaurants. Wayzata, MN: DCI Publishing.

Kane, J.K. (1990) Coping with fad diets. New York: Rosen Publishing.

Natow, A.B., and J. Heslin. (1985) No-nonsense nutrition for kids. New York: McGraw-Hill.

Additional sources of information:

Health Education Services
P.O. Box 7126
Albany, NY 12224
(printed materials and audio tapes: Nutrition for Life)

U.S. Department of Agriculture
Human Nutrition Information Service
Room 360
6505 Belcrest Road,
Hyattsville, MD 20782
(materials about the food pyramid)

Community resources:

Public-health nutritionist
University department of food and nutrition
Family-practice doctor

Main Activity

Lunch at Fast-Food Freddy's
Find out the nutritional value of fast-food.

One fast-food meal, heavy in calories and fat, can be balanced by eating other nutritious meals during the day. But, too many fast-food meals can throw your body out of balance. You will figure out the nutritional values of foods to understand the nature of a healthy diet.


  1. Select some students to collect nutrition information from their favorite fast-food restaurants. Or, refer to the Resources section for books that contain this information.
  2. Share the cash-register graphic with your students and ask them to order their favorite lunch from Fast-Food Freddy's. Make a list of each order.
  3. Using the fast-food restaurant's nutrition information, have students determine the approximate number of calories, fat, protein, and carbo-hydrates from their imaginary lunches.
  4. Review the food pyramid. Which foods should eat the most of on a daily basis? Which foods the least?
  5. Referring to the fast-food nutrition pamphlets, ask students to reorder their lunch from Freddy's, substituting foods with fewer calories and fats.
  6. Divide students into groups. Assign each group a popular fast-food restaurant and determine a nutritional meal using the actual nutrition information from that restaurant. Remind students to pay particular attention to the amount of fat and calories for each food item. Have students present their menus to the class and explain their choices.


1. What fast foods do you eat regularly? What are the calorie and fat contents of these foods? What satisfying substitutes might you choose that have less fat and fewer calories?

2. If you ate a fast-food lunch everyday, what would you have for breakfast and dinner to make your entire daily-food intake well-balanced and nutritional?

Does advertising influence your choices of foods? Record on audio tape or videotape a food commercial. As a class, listen to or watch the tape, and then discuss the commercial's effectiveness. Buy the advertised food and study the nutritional label on the package. Is it really as good as the commercial says it is?

Compare the nutritional value of meals from various cultures. Calculate the total calories and nutritional content of a typical American meal. Look through ethnic cookbooks and create dinner menus that reflect Chinese, Mexican, and Italian meals. Tally the total calories and nutritional content of these dinners. Which meal might be the healthiest?

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