Full Menu Close Menu

Human Nutrition

  1. Exploring good food habits: Grades 2-3, Duration: six to eight weeks
  2. Understanding different methods of doing scientific research using human nutrition as an example: Grades 6-8, Duration: six to eight weeks

Developed by: Charles Stahler and Reed Mangels, PhD, R.D., Vegetarian Resource Group

Science Objective #7: Document epidemiological, case study and experimental research that advances human health without dependence on animal experimentation.

A. Exploring Good Food Habits: Grades 2-3

UNIT OVERVIEW: The United States Department of Agriculture has recommended that we used the Food Guide Pyramid in making daily food choices. Students would begin to understand how food choices are made and which choices we should make. Health studies on how food choices are made can be done without using animal experimentation.

PERFORMANCE OBJECTIVE I: Students will become familiar with the pyramid chart.

ACTIVITIES: Have students cut out pictures of food from magazines and newspapers. On poster board or oak tag have students print the different categories of foods: )1 breads, cereals, pastas; 2)vegetables; 3) fruits; 4)dairy group; 5) dry beans, eggs, meat, poultry, fish; 6) fats and oils.

Write the servings recommended under each category:

1) breads, cereals, pastas (6-11 servings)
2) vegetables (3-5 servings)
3) fruits (2-4 servings)
4) dairy group (2-3 servings)
5) dry beans, eggs, nuts, meat, poultry, fish (2-3 servings); and
6) fats and oils (use sparingly)

Which foods should you eat most? Which foods should you eat least?

PERFORMANCE OBJECTIVE II: Students will learn which foods go with which part of the pyramid.

ACTIVITY: Have the students cut out pictures of foods from magazines and newspapers. Have then paste or tape the pictures in the appropriate category on their poster board.

OPTIONAL: Have the students cut out pictures of foods from magazines and newspapers. have them paste or tape the pictures in the appropriate category on their poster board.

PERFORMANCE OBJECTIVE III: Begin to understand how food choices are made.

MOTIVATION: Ask the students why they choose to eat the foods they do. Do they choose a food because it is healthy? Or because their friends eat that food?

1) Ask the student which foods they eat that their parents eat? Which foods do they eat which their friends also eat? Do they eat any foods which do not taste god to them? If so, why? Do they choose foods because they are healthy? If not, why do they choose the foods they eat?

2) Have each student pretend he or she is from another country e.g. Italy or China. Which foods do they think they would eat?

SCIENCE FAIR PROJECT; UNDERSTANDING HOW PEOPLE MAKE FOOD CHOICES.

1) Bring in foods and set up a store or restaurant. Have different students and adults shop or buy at the restaurant. Note their food choices. Ask them why they chose what they did. Did males and females make similar food choices? Did adults make similar food choices? Did people from similar ethnic groups make similar food choices?

2) Observe, in a store, what foods people buy. Do younger people buy different foods from older people? Do athletic people buy certain foods? Does price affect which foods people buy?

3) Observe in a supermarket whether healthy foods are easy to reach. Are less healthy foods high up or easy to reach? Which kinds of foods are closest to the checkout counters, more healthy or less healthy foods?

4) With a parent/guardian or teacher, observe in restaurants whether more healthy or less healthy foods are featured. In one part of the food pyramid emphasized more than another in the restaurant menu or in food displays behind the counter?

5) Do the same kind of observations at a street fair.

B. Understanding Different Methods of doing Scientific Research Using Human Nutrition as an Example: Grades 6-8

BACKGROUND: Scientists do research on human health in three general ways:

1) They study different populations (over large geographical areas) and try to learn what factors cause different levels of health and disease.

2) They set up an experiment (clinical study) where they can study a small number of people.

3) They set up a study where they use non-humans as subjects. For example, the scientists may do an experiment involving animals, plants, computers or other technology. Each type of research has strengths and limitations.

UNIT OVERVIEW: This unit will help students understand the different ways of doing research and the strengths and limitations of each. In order to give students a practical understanding, the activities will focus on human nutrition.

PERFORMANCE OBJECTIVE 1: Students will understand that there are three major ways (methods) of doing scientific research on human health. These are 1) population (epidemiological) studies of large groups of people such as an ethnic group or an entire country; 2) studies on a small number of people (case or clinical studies); and 3) experimental research using non-humans as the subjects.

MOTIVATION: Have students bring in articles from newspapers or magazine about health studies. For example, the media is full of studies about the newest drug, influence of certain foods, health problems from pollution, etc.

ACTIVITY 1: Explain to the students the different ways of doing research. Give examples of each and ask the students to identify each type of research.

Optional: Have students make up experiments and tell which type of research each experiment would be.

ACTIVITY 2: Have students bring in a newspaper or magazine. Ask them to cut out articles which talk about human health studies. Have each student tell which type of research each article is describing: population, case or clinical study, or experimental research on non-human subjects.

Optional:

  • Have the students tape the articles onto paper and label each according to type of research.
  • Make up a scrapbook for: 1) population studies, 2) case studies and 3) other experimental research.
  • File the articles in the appropriate book.
  • You can list the articles on the chalkboard or on a computer if it is available in the classroom.
  • Do any of the articles refer to more than one type of research

ACTIVITY 3: Students should tell which type of research has been used in each case, i.e. population study (PS), clinical study (CS), or research on non-human subjects (NHS). Teachers may wish to use this page as class quiz sheet. In that case, delete the answers in brackets before photocopying for students.

1. During World War I, Denmark was blockaded by the allies. The death rate from disease fell when almost the whole country was placed on a vegetarian diet. (PS)

2. During World War II, when restrictions on meat consumption were imposed on Norway because of the German occupation, death rates from heart disease and diabetes fell. (PS)

3. Autopsy studies on soldiers killed during the Korean War revealed "hardening of the arteries" among Americans, but not among the Koreans who ate a diet less centered on meat. (PS)

4. A scientist from Cornell University in New York studied 6,500 men and women living in China. The scientist noted that very few Chinese are overweight, as compared to people in the United States. (PS)

5. A 1973 study in Boston compared a small group of meat eaters to a group of vegetarians. The meat eaters had higher blood cholesterol. (CS)

6. Scientist at the United States Department of Agriculture gave one group of people vitamin C tablets and another group are large portions of vegetables containing the same amount of vitamin C. The scientists wanted to know if vitamin C from one source was better than that from another source. (CS)

7. Scientists had one group of children eat a typical American diet. Another group followed a special diet which had no food additives. The scientists saw no difference in behavior between the children in each group. (Cs)

8. Scientists wanted to know how much vitamin C is in broccoli. To find out they put the broccoli in a test tube with chemicals to see the reactions. (NHS)

9. Scientists wanted to know if the calcium in limestone is the same as that in broccoli. They put the broccoli in a beaker with chemicals to see the reaction. (NHS)

10. Some scientists believe that humans need 400 milligrams of calcium while others believe they need 1,200 milligrams of calcium a day. The scientists used a computer program to construct the two diets containing either 400 or 1,200 milligrams of calcium and compared the two diets for the amount of fat, rion and other nutrients. (NHS)

11. Scientists observed what chimpanzees eat in the wild. They set up a hidden video camera in the jungle. (NHS)

PERFORMANCE OBJECTIVE II: Students will understand the strengths and limitations of a population study.

The major strength of populations studies is that they are able to look at large groups of people. Often people from more than one region or more than one country are included in a population study. The size of this kind of study can give information about a variety of ages as well as the effect of gender or ethnic origin. Population studies look at humans and do not have to be interpreted by looking indirectly at studies of animals, computers programs, etc.

There are limitations to population studies. It is difficult to collect accurate information from many people over a large period of time. Scientists often don't know all the factors influencing the subjects. For example, if you are studying and recording the influence of diet, what if there is also pollution or some people smoke and others do not?

ACTIVITY 1: Give examples of how you can predict behavior from looking at the previous experiences of a large group. For example, ask what time everybody went to lunch yesterday. Ask what time everybody went home yesterday. Ask what time you would expect everybody to go to lunch and go home today.

Have each child record what time they go to lunch and go home today. Compare results tomorrow. did most children go to lunch and go home at the times expected? Were there any exceptions? What caused the exceptions? How well do the children think you can predict behavior based on the results of looking at the experience of the whole class?

ACTIVITY 2: Have the children name all the countries they know. Write these on the chalkboard.

Ask the children how easy it would be to interview people from all these countries. Would there be language difficulties? How much would you have to know about different foods and ways of preparing foods? Would it be hard to get information from countries where there were no dictatorships? How hard would it be to get information from people who did not live in cities? How would you decide how many people to talk to from each country?

ACTIVITY 3: Have the students pretend they wanted to do a study on what people eat. Have them write down what they ate yesterday, one day last week, one day last month or maybe even one day last year. How well did they remember?

Optional: If the school has a cafeteria or serves a snack, have the students write down what they think was served last week. Then state what was served. so as not to embarrass them, they need not say what they wrote. Have the ones who remembered exactly what was served raise their hands. even if they did remember what was served, can they remember what they ate?

ACTIVITY 4: Have the students name food they eat on Thanksgiving. Then have them discuss similarities and differences and reasons for these differences, (ethnic, religious, time to prepare foods, likes and dislikes.)

Have the students name foods that they eat when they are happy and discuss why certain foods are selected.

PERFORMANCE OBJECTIVE III: Students will understand the strengths and limitations of a clinical study.

Clinical studies also use human subject, but these studies are often smaller than population studies. These studies modify (change) a person's activity and then the effects of these changes are studies.

As with population studies, an advantage of clinical studies is that they use human subject, so the results o these studies are easily applied to humans. As additional strength of clinical studies is that they are more controlled, i.e. the experimenter can choose and change different parts of the study. In a population study you are unable to control what the people choose to do. often in a clinical study for nutrition, subjects are housed in a special, scientific laboratory where all food is provided and where activity is closely monitored. this allows scientists to know exactly what is going on with their subject. However, results may be quite different from those of a free-living group who can make different choices.

ACTIVITY 1: Have the students eat their snack or lunch at the normal time. Have then record how much and what they ate. have them bring in the same food the next day but have them eat at a different time. Have them record how much of each food they ate. Compare the different amounts.

ACTIVITY 2: Make up solutions of different intensities of sweetness. For example, add one-half teaspoon of sugar to one glass of water, two teaspoons to another glass of water, three to another, etc. Have the students taste and write down which does not taste sweet. Are there any differences by gender? What if students are grouped by how many sweets they usually eat? Are there any differences?

ACTIVITY 3: Ask the students to watch three hours of television on a Saturday morning and write down anything they eat or drink while watching. the next Saturday tell them not to watch any television. They should, however, write down everything they eat or drink for three hours. Could television watching affect food choices? What other factors could be significant, e.g. being too busy to eat, or parents only allowing them to eat at certain times?

PERFORMANCE OBJECTIVE IV: Students will understand the strengths and limitations of non-human experiments.

Non-human studies are used because they allow investigators to have more control than is possible in human studies. Tests are often performed which ethically would not be performed on humans. These studies may be less expensive than human clinical or population studies.

Sometimes animals are used in non-human studies. Many people have ethical reasons for not wanting to do experiments on animals. Ethical issues aside, a major concern with doing non-human studies is the question of whether or not results from non-human studies are applicable to humans. Vitamin C, for example, is an essential nutrient for humans but not for rats or rabbits.

Some of these differences between humans and non-humans are known, so certain animals or objects may not be used for some experiments. For example, vitamin C studies would not usually be done in rats or rabbits since vitamin C is an essential nutrient for humans, but not for rats or rabbits. In other cases the response of animals and that of humans is not known or controversial. In these cases, assuming that humans would respond the same way that animals

The advantages of using computers are that you can have more control and easily change the variables. Computers may be cheaper and easier to use than people or animals. However we do not yet have enough computer knowledge to reproduce all human reactions by computer. A computer is at present unable to account for all the reactions of different people.

ACTIVITY 4: Three scientists are trying to get a grant to study heart disease and cancer. Scientist A wants to do a population study (PS). Scientists B wants to perform a clinical study (CS). Scientists C wants to perform a noon-human study (NHS). Have the students decide which scientist made each statement below. (The statements can have more than one answer. If you disagree with a student's answer, have them give you a reason why they choose that one.

  • Chinese have lower rates of heart disease than Americans.
  • Chinese eat low-fat diets.
  • Low rates of heart disease among Chinese are due to their not smoking.
  • I believe Chinese have low heart disease rates because they eat a lot of rice. I want to have twenty Chinese eat their normal diet except for rice and see what happens.
  • It is too difficult to obtain the blood samples I need from that population.
  • Using computer software would be the least expensive way to compare the two types of data.
  • I have placed an ad in a paper in order to find the control group
  • People who consume large amounts of vitamin A do not tend to get cancer.
  • At this point, it is unethical to test this drug on people.
  • My patients only have a few months to live. They would like to try this experimental drug.

Possible Science Fair Projects Performing Health Studies Without Dependence on Animal Experimentation

The American Heart Association, the American Cancer Society, the National Cancer Institute and other health agencies have recommended that Americans eat more fruits and vegetables and less fatty foods.

I. Survey specific recommendation being given out.

1) Call different health agencies and ask them specifically what foods they would recommend that people eat. Are the answers the same?

  • Contact health educators for schools and public agencies. Find out what foods they are telling people to eat. Compare these to the health agency recommendations. Are they the same?
  • Survey agencies which deal with people such as Boy Scouts, Girl Scouts, other youth groups, etc. what kinds of foods do they tell people to eat?
  • Are the results similar? Are the recommendation contradicting and confusing? What suggestions would you make for agencies to promote healthier eating habits?

2) Are places which serve food following recommendations of health agencies? Survey the foods served in school cafeterias, train terminals, restaurants, snack bars, fast food chains, etc. Do these foods conform to recommendations made by health agencies?

3) When healthy foods are served in school or other places, survey how well they sell.

II. Survey why people eat the way they do.

Put together a questionnaire asking what foods people eat and why. Compare different ethnic groups, different sexes, ages, etc. Do you see patterns? How would you use the motivations for eating to help people adapt to healthier diets? Take into consideration taste, economics, prestige, background, ethics, religion, habit, availability politics and advertising.

III. Can you affect people's eating habits?

1) As a control group, survey the eating patterns of students in one classroom. Then try different strategies to see if you can affect students' eating habits.

2) Have a student obtain information from the American Heart Association. Bring in a speaker from this or another health group. Then survey the eating habits of the students after a week or two. Compare to see if education had any effect on eating habits.

3) Survey another class. See if their eating habits are different from those of your class. Put up signs in the school promoting good eating habits. Then survey the other class again to see if their eating habits have changed. Record the changes.

4) Have a bake sale where you sell healthy food and give out literature that promotes healthy eating habits. Survey the school afterwards to see if this changes eating habits.

5) Show a video on eating healthy foods. See if this influences eating habits.

6) Take a field trip to a grocery store or farmers' market. Point out healthy foods. See if this influences eating habits.

IV. Do research to find out if you can see relationships between eating patterns and disease.

Contact your local health department to see if you can get rates of death and causes in different parts of the city or state. Look at the food habits in each area by interviewing people, looking at restaurant menus, local advertisements and by seeing what is sold in grocery stores. Are there differences in the foods sold in each area? Do these correlate with different disease and death rates?

BIBLIOGRAPHY

The American Heart Association. Contact the local chapter in the telephone book.

"Creative Food Experience for Children", from Center for Science in the Public Interest, 1875 Connecticut Avenue, N>W> Washington, DC 20009-5728

"Mathematics and Global Survival", by Richard Schwartz (contact Richard Schwartz, #H7, Mathematics Department, C.U.N.Y., Sunnyside Campus, Staten Island NY 10301

"I Love Animals and Broccoli Activity Book", The Vegetarian Resource Group, P.O. Box 1463, Baltimore, MD 21203

"Simply Vegan" with a complete nutrition section by Reed Mangels, Ph.D., R.D., The Vegetarian Resource Group, P.O. Box 1463, Baltimore, MD 21203.