LESSON 1: A Food Pyramid Built From Corn
SUBJECT: Science
OBJECTIVE: Students will learn the multiple roles of corn in the USDA Food Guide Pyramid, and will build their own corny one.
MEASUREMENT: Students understand the Food Pyramid and understand the importance of corn in it.
BACKGROUND FOR TEACHERS:
The Food Guide Pyramid is an outline of what to eat each day based on the USDA 1995 Dietary Guidelines. It's not a rigid prescription but a general guide. It calls for eating a variety of foods that will provide the vitamins, minerals, carbohydrates and protein needed for good health.
Meat is an extremely important part of the American diet. It is also important worldwide. When per capita income rises in any country, meat consumption also generally increases. Unit 8 discusses the export of corn worldwide, which is closely linked to both per capita income and animal agriculture in those countries.
Corn is a key link in the meat production chain. It's a very important ingredient in animal feed, providing the major source of energy, as well as many other nutrients.
- Many new kinds of corn are being developed that can meet the nutritional needs of animals even better. Unit 4 discusses the genetic advances being made. For pigs specifically, there are now corn hybrids available that provide higher oil levels. Oil or fat has approximately 2.2 times more metabolizable energy value than carbohydrate so is a greater energy source for animals requiring energy dense diets-such as growing pigs. (See http://www.ext.vt.edu/news/ periodicals/livestock/aps-98_04/aps-904.html for more information on high oil corn.) There are also corn hybrids available with specific amino acid (lysine) or enzyme (phytase) levels that are important in hog production.
Corn is therefore a very important component of the Food Guide Pyramid! As a food/cereal grain, it can be found in the foundation level. As a vegetable, it can be found in the middle level. As a hugely important component of livestock diets, it plays a key role in the meat category. It is also a component of the oils and sweet things that make up the very tip of the Pyramid! (See Unit 9 for more information on food uses of corn.)
STUDENT ACTIVITIES:
1. Ask students to read the story Ann Learns a Secret Family Recipe. Then discuss the "recipe." Ann is learning to provide the proper diet for pigs so they can stay healthy and grow fast! Their diet is balanced: it has corn as a foundation (3/4 of a wagonload), then has concentrate added which includes protein from soybean meal, and many vitamins and minerals. The food for these pigs must be nutritious. It must be ground into small enough pieces that it can be easily eaten.
- If it's possible, this would be a good time to let the students look at various kinds of animal feeds. Samples are available from feed stores, farm cooperatives or local farmers. Students can read the labels or ask exactly what ingredients are in the feed. (Sometimes feeds include medications or growth hormones, so don't let the students taste the feed unless you know all the ingredients.)
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Dog food, cat food, bird food and fish food are available at pet stores, and can be used to make the point that's important here: Animals need a balanced diet, just as children do!
2.Be sure to point out how important corn is for animal feed. (Lesson 2 provides statistics that document the importance of corn for animals.) Even dog food uses corn as a major ingredient!
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Ask students why they think corn is so important in all these feeds. You can refer them back to the story in which Ann learns that corn is rich in carbohydrates and provides ENERGY for animals and humans. (Unit 7, Lesson 1 talks about Corn for Energy in another respect-energy to run our cars and other engines. )
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But this kind of energy is the kind that fuels the cells in our body! Older students might want to study this more, and write a report on carbohydrates as a fuel source that powers our body. This fits well into a study of metabolism and calories.
3. Show students the picture of the USDA Food Pyramid and describe each category and the number of servings recommended per day. (Example 1)
4. Ask students to create a 3-D model of the Food Pyramid. This can be made from Legos, clay, paper, fabric, wood, metal, building blocks, corn, pillows, or anything they can think of. They can use real food (dried only), paper, or clay models to represent the food groups.
5. Ask students to complete at least one of the following. Others can be done for extra credit.
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Keep track of their meals for a week, completing a chart that shows how many servings they ate from each category each day. Give extra credit if they highlight the foods made from corn.
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Plan a meal that is balanced between the five essential food groups. Then cook it and serve it to their family, or the class!
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Write a commercial for corn, highlighting its importance in so many of the Food Pyramid categories. Then present it to the class.
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If enough students do this project, have them vote for the CORNIEST one, and give a (corn-based) food prize.
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Complete the Food Pyramid exercise at http://www.kidsfood.org/f_pyramid/pyramid.html
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Choose one of the food groups and write a report about corn's role in that group. (Unit 9 will help.)
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KEY ISSUES
