This is the second Investigation of the LabLearner CELL Exploring Nutrition. In it, students will learn to understand both the MyPlate graphic from the USDA as well as nutrition labels on the packaging of foods.

Note to Teacher: The Student Data Record is set up to conduct a “play” in PreLab of a student going to a doctor (Dr. Greene) where the USDA MyPlate graphic is discussed. While you may wish to follow this concept, the slides and annotations presented in this slide set will accomplish the same purpose in somewhat less time. 

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A. Begin the Investigation by reviewing some of the concepts that students learned in Investigation One. Initiate a discussion by asking students the questions that follow:

1. Ask students: How is food changed so that our bodies can use it? Students should indicate that the organs and parts of the digestive system use the process of digestion to make food usable by our bodies.  Food is digested or broken into smaller pieces or substances that the body can use.

2. Ask students: What are the parts of the digestive system and their functions? The mouth is where food is placed.  The teeth and tongue are used to chew, grind, and mix food with saliva.  The throat serves as a passageway to the esophagus, where food is pushed into the stomach.  Acids and enzymes in the stomach digest food into smaller pieces, which move into the small intestine.  Enzymes in the small intestine digest food further.  Nutrients in the digested food pass through the walls of the small intestine and into blood vessels, where they are transported to the body’s tissues.  In the large intestine, water and some vitamins are absorbed.  Any undigested food then moves through the large intestine and is passed out of the body as waste.

3. Ask students:  When does mechanical digestion occur in the digestive system?  What happens to the food during mechanical digestion? Mechanical digestion occurs in the first stages of food digestion.  The food enters the mouth where it is chewed by teeth.  The food is mixed with saliva by the tongue and swallowed, then moves through the throat to the stomach.  In the stomach, food is broken down into smaller pieces by mixing and grinding.  During mechanical digestion, the food undergoes physical changes in it size and shape, but does not change chemically.

4. Ask students: When does chemical digestion occur in the digestive system?  What happens to the food during chemical digestion? Food is chemically digested in the mouth, stomach, and small intestine.  When food is in the mouth, the teeth and tongue break food into smaller pieces by mechanical digestion. As food is mixed with saliva, enzymes in the saliva begin to break food down by chemical digestion. When food reaches the stomach it undergoes some mechanical digestion through grinding and mixing, but also undergoes chemical digestion as the acids and enzymes in the stomach act on the food, breaking it into smaller, new substances. Chemical digestion also occurs in the small intestine.  Chemical digestion is the breakdown of food into even smaller particles than those that result from mechanical digestion.  Food undergoes a chemical change during chemical digestion and the resulting smaller particles are new substances. Ultimately, chemical digestion breaks food down into nutrients.

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B. Relate the digestive process to the importance of providing the body with the appropriate balance of nutrients for optimum health.  Ask students to locate their Scientist’s Glossary. Review the definitions for the terms nutrition, nutrient, nutrition label, serving size, MyPlate, Daily Value,  and Percent Daily Value (%DV) as a class.

1. Explain to students that a special group of scientists study how the body uses foods to stay healthy.  

Ask students: Can you think of what the name for this type of science might be? Students should indicate that nutrition is the name for this type of science.

2. Tell students that nutritionists have studied what foods and nutrients the human body needs to be healthy.

3. Remind students that nutrients are those substances that the body requires in order to stay healthy and to function.  There are six major types of nutrients: vitamins, minerals, carbohydrates, lipids (fats), protein and water.  Each nutrient found in food is important because each performs a different function that allows the human body to work properly.

4. Ask students:  What should you eat in order to stay healthy?  How do you know what foods you should choose to be in good health? Student answers may vary.

5. Explain to students that nutritionists have developed guidelines and information that people can use to select foods that will help them stay healthy.

a. One type of guideline is the MyPlate graphic (refer to slide). Scientists developed MyPlate based on the different types of nutrients that the body needs to remain healthy and the different types of foods that contain these nutrients.

• Explain that this MyPlate graphic divides foods into groups or categories.  Direct students to look in their Student’s Glossary at the definition for a food group.  Foods are organized into group because they may be similar in where they come from and in the nutrients they contain.
• The guide also lists the recommended amounts people should eat daily from each group or category.

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b. Tell students that another source of information is a nutrition label. Explain that nutrition labels are found on the packaging of many foods.  The label lists nutrients that can be found in that particular food item.

• Explain that the nutrition label of a food item identifies the serving size for that item. A serving size is a way that nutritionists can indicate the size of one portion of food. The serving size listed on a nutrition label helps people to understand how much of each nutrient they are eating in one portion of that food. Tell students that the serving size on a nutrition label can be different for different foods.
• Explain that a nutrition label lists the amounts of certain nutrients found in that food item.  The nutrition label is required to list information known as the Percent Daily Value (%DV) for specific nutrients.  The %DV of a nutrient is the percentage, or part of the total amount, required daily for a healthy individual based on scientific knowledge.

6. Tell students that they will be learning more about how to use the MyPlate graphic and nutrition labels as they progress through this CELL.

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C. Explain to students that they will perform a short play that will help them better understand how the MyPlate graphic and nutrition labels might be used.  Divide students into groups of three and encourage them to take on the roles of the characters in the story, narrator, Jason and Dr. Greene.

1. Ask students to locate problem 1 of their Scientist Data Record.

2. Students will read:

Narrator:  Jason is in the 4th grade.  He is a good student and an excellent runner.  He competes at the local YMCA and hopes to compete in the Olympic Games in the future. Jason knows he must exercise every day to be a top athlete.  He also realizes that he needs to eat nutritious foods.

Jason is not sure how to do this, so his parents take him to their physician, Dr. Greene. Dr. Greene gives Jason a picture of the MyPlate graphic.

Dr. Greene:  Jason, one way to make healthy food choices is to follow this guide by eating the daily amount recommended for each of the food groups and categories.  The MyPlate graphic represents the different food groups or categories as bands.

Explain that one way to make healthy food choices is to follow MyPlate by eating the daily amount recommended for each of the food groups and categories.  MyPlate represents the different food groups as portions on a plate. The USDA created MyPlate in order to help people eat healthily and follow the USDA Dietary Guidelines. The USDA Dietary Guidelines suggest:

• Making half of your plate fruit and vegetables.

• Focusing on whole fruits. Try to eat or drink about 475 ml of fruit every day.

• Varying your vegetables. You should eat about 590 ml of vegetables every day.

• Making one-quarter of your plate grains and making half of the grains whole grains. Grains include bread, cereals, rice, and pasta.  You should eat about 170 g of foods from this group each day.

• Making one-quarter of your plate proteins and varying your proteins. Proteins can also be thought of as the meat and beans group.  You should eat about 142 g of meat, poultry, fish, dry beans, eggs, or nuts each day.

• Including sources of dairy each day. The dairy food group includes milk, yogurt, cheese, and other milk products.  You should eat or drink about 710 ml every day from this group. If possible, move to low-fat and fat-free milk or yogurt.

• Reducing the amount of oils you eat each day to about 25 ml. Choose oils versus fats.

• Limiting foods and drinks with sodium, saturated fats, and added sugars. You should eat these sparingly, or very few foods, from this category each day.

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3. As student groups reach this part of the play, ask them to stop so that you can discuss information that relates to food choices.  Encourage students to return to their seats.  Refer to this slide as a visual aid while conducting a class discussion about this concept. The following directions are provided to assist with the discussion and include questions that may be helpful in prompting student discussion.

a. Encourage students to study the foods displayed in the food groups.  

Ask students:  Why do you think different food groups are different sizes on the plate? Students should indicate that it is important to include the different groups in each meal. By doing this, it helps you to eat all of the nutrients you need for good health. The plate helps to show each meal should try to include all of the food groups.

b. Direct students’ attention to the band that represents the grains food group.  

Ask students: What are some different types of grains? Student answers may vary.

• Explain to students that the grains food group is divided into foods that are made of whole grains and foods that have been refined.  Refined grains are whole grains that go through a process that removes parts of the grain called bran and germ. This process removes some of the nutrients in the grain, so manufacturers add some nutrients back into them.  This is why they are called “enriched.”  But even when these refined grains are enriched, they are still not as healthy as whole grain foods.

• Ask students:  What do you think are examples of refined grains? Student answers may vary.  

Examples of refined grains include white flour, white bread, pasta, and white rice.

• Ask students: What do you think are examples of whole-grain foods? Student answers may vary.

Tell students that examples of whole grains include brown rice and whole-wheat products such as flour, bread, crackers, and pasta.  Wild rice, oatmeal, whole cornmeal, barley, rye, and a grain called bulgur, which is also called cracked wheat, and popcorn are some other examples.

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c. Continue this process by discussing the vegetable group.  During the discussion, include that it is important to eat a wide variety of vegetables, such as dark green vegetables, orange vegetables, and beans.

Just over a quarter of your plate should contain vegetables. Vary your vegetables. You should eat about 590 ml (2 1/2 cups) of vegetables every day.

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d. Repeat the process for the fruits (this slide) and dairy (next slide) groups.  Point out that natural fruits are better than fruit juices. Focus on whole fruits. Try to eat or drink about 475 ml (2 cups) of fruit every day. 

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Dairy Group:

Include sources of dairy in your diet each day. The dairy food group includes milk, yogurt, cheese, and other milk products. You should eat or drink about 710 ml (3 cups) every day from this group. If possible, move to low-fat and fat-free milk or yogurt.

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e. Discuss the protein (meat and beans) group with students.  Explain to students that they should vary the types of foods they eat in this group, selecting lower fat or lean choices.

• Explain that some fatty cuts of meat, such as a hot dog, bologna, or a high-fat hamburger are considered less healthy foods and should be eaten less than the other healthy foods in this group, such as lean chicken, turkey, and fish.

• Tell students that beans, nuts, seeds, and peas are also foods included in this group.

Ask students:  Are any of your food choices from this food group included in another food group? Students should indicate that beans and peas are also food selections in the vegetable group.

Ask students:  Why do you think beans and peas can be included in two different groups? Student answers will vary.

• Remind students of the definition of a food group, a group of foods that have a similar mix of nutrients.

• Explain to students that some foods can fit into more than one group or category because of the types of nutrients they contain.  Beans and peas are considered vegetables because of how they are grown, but they contain some nutrients similar to foods in the protein group.  This is why they are considered part of both groups.

Make one-quarter of your plate proteins and vary your proteins. Proteins can also be thought of as the meat and beans group.  You should eat about 142 g (5 oz.) of meat, poultry, fish, dry beans, eggs, or nuts each day.

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f. Tell students that oils and limited foods are a part of the MyPlate graphic.

Ask students:  What do you think is included in the oils group? Student answers may vary. Guide them to suggest items such as vegetable, canola, olive, and peanut oils.

• Most of the time oils are not eaten alone.  Some oils are found naturally in foods. Other times oil is an ingredient that is combined with or added to other foods. Healthy oils contain nutrients that are necessary to the function of the human body.

Ask students:  Can you think of any foods that contain a high amount of oil? Students may suggest soft margarine, mayonnaise, salad dressings, peanut butter, seeds and nuts, and fried foods.

Reducing the amount of oils you eat each day to about 25 ml. Choose oils versus fats.

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g. Review the limited foods category.  Explain that foods such as cake, cookies, and candy belong in this category.

Ask students:  Why do you think these food items are grouped together in this category? Student answers may vary.

• Guide students toward understanding that these food items are grouped together because they are high in an ingredient, added sugars, and do not contain nutrients that are essential to the function of the human body.

• Explain that the food items in this category should only be eaten sparingly, which means that they should be eaten as little as possible because they have little nutritional value.  This is why this category does not have a recommended daily amount listed.

Limiting foods and drinks with sodium, saturated fats, and added sugars. You should eat these sparingly, or very few foods, from this category each day.

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Conclude this part of the Investigation by telling students that they will conduct experiments in this Investigation that will increase their understanding of how to use the MyPlate graphic and the nutrition labels on food items.  

As they conduct their experiments in Lab, they should think about the following questions:

What foods are in each of the food groups or categories?

How can I use the information on nutrition labels to help me make healthy food choices?

Gilbert made the healthier food choice for lunch. He took a chicken taco, tomato soup, and milk. Sarah, on the other hand, took a huge multideck grilled hamburger, fries, and a sugary soda.