BioEd Online

Teacher Background

The brain needs many different kinds of nutrients. Glucose, a kind of sugar, is the main source of energy for the brain. While all carbohydrates can serve as sources of glucose, some are better than others. Breads, pastas, cereals and other foods made with whole grains provide the brain with steady supplies of glucose. Foods that contain white sugar or corn syrup, white rice, white flour (found in white bread and most cakes, crackers and cookies) and other refined carbohydrates also supply energy. However, they cause glucose levels in the bloodstream to rise rapidly and then crash.

Proteins from food provide the amino acids used to make neurotransmitter molecules. Meat, fish, poultry, dairy products, eggs and beans (including soy beans) are good sources of proteins. The cell membranes of neurons are made of fats. The healthiest fats are liquid at room temperature. Olive, flaxseed and canola oils are examples of healthy fats. In addition, oils from coldwater fish, such as mackerel, salmon and trout are good sources of a kind of fat needed to build cell membranes in the brain.

Minerals such as calcium, sodium and potassium are vital for the generation and conduction of electrical impulses in neurons and are involved in the release of neurotransmitters from axon terminals. Vitamins are essential molecules needed in small amounts by cells throughout the body, including neurons. For example, choline, a vitamin found in egg yolks and leafy green vegetables, is the basis for the chemical messenger, acetylcholine, that transmits signals to muscles.

The diets of many adolescents are high in sugars and unhealthy fats. In addition, the “supersized portions” of snack and fast foods eaten by many students supply too many calories. Calories measure the amount of energy provided by food. They can be obtained from the breakdown of many different kinds of molecules, particularly fats, carbohydrates and proteins. The body needs a certain amount of calories each day as fuel.

Excess calories are stored as body fat. Unfortunately, even though many American children consume several times the amount of calories they actually need, they are not supplying their bodies with nutrients needed for optimum growth and development.

This activity is designed to promote student awareness of portion sizes, nutrient content of food, and the brain’s nutritional needs.

Objectives and Standards

Concepts

• The brain needs many different kinds of raw materials from food.

• Breakfast is important.

• Recommended serving sizes are often smaller than the size actually served or the amounts people eat.

Science, Health and Math Skills

• Observing

• Recording

• Inferring

• Drawing conclusions

Materials and Setup

Teacher Materials

• One or more medium or large frozen pizzas with mixed (or "supreme") toppings

Materials per Group of Students

• 2 craft sticks

• 18-in. sheet of wax paper

• Prepared and cooled slice of frozen “supreme” pizza

• Copy of “Dissect That Pizza!” sheet

Materials per Student

• Copy of the “Nutrition Facts” label from the pizza package

• Copy of the student sheets

Optional Demonstration

• 2 slices of presliced, prepackaged sandwich cheese

• Medium apple or orange (medium)

• Cup of raw, chopped carrots

• Deck of cards

• Slice of sandwich bread

• Teaspoon of butter or margarine

Setup

1. Before class, bake one or more medium or large frozen pizzas with mixed or “supreme” toppings. Let the pizzas cool (refrigerate if necessary). Cut each pizza into the number of slices (serving sizes) recommended by the Nutrition Facts label on the pizza package. You will need at least one slice per group.

2. Make one copy of the Nutrition Facts label from the pizza package for each student. Photocopy “Dissect That Pizza!” (one per group), and the remaining student pages (one per student).

   Optional. If possible, bring the following items to use for demonstration with Step 2 below: 2 slices of cheese (milk products); 1 slice of bread (carbohydrates); 1 cup carrots (vegetables); 1 medium apple or orange (fruit); 1 teaspoon of butter or margarine (fats and oils); and 1 deck of cards (to model 1 portion for meats, fish and poultry).

3. Have students conduct this activity in groups of 2–4.

Procedure and Extensions

1. Ask students, What do you think your brain needs to function? Students might respond that it needs some sort of food or fuel. Tell students that they will conduct an investigation of a popular food item to examine portion size and the amount and quality of brain food (or fuel) it provides.

2. Give each student a copy of the “Healthy Plates,” and “Estimates & Servings” pages. If time allows, have students complete the questions at the top of the “Healthy Plates” sheet. Discuss the portion sizes shown by the “Quick Hand Measures” and the recommendtions on the “Healthy Eating Plate.”
   
   Optional. Show students actual serving size samples from each of the food groups.

3. Tell students that they are going to examine and dissect a popular food, pizza. But first, ask students, What are the ingredients in a pizza? Students probably will respond—crust, meat (various kinds), cheese, sauce and vegetables. Ask, Do you think pizza is good for you or meets some of your daily nutritional requirements? Why or why not? Record responses on the board.

4. Next, give each group of students a “Dissect That Pizza!” student sheet, a serving of pizza, a large piece of wax paper for a work surface, 2 craft sticks to use for the dissection and a copy of the “Nutrition Facts” label from the pizza package.

5. Have each group follow the directions on the student sheet and answer the questions. Next, have groups share their conclusions with the class. Ask, How does pizza rate as a healthy food?

6. Explain that fats and calories are only part of the story. To function at an optimal level, the brain needs specific nutrients. Give each student a copy of “Fueling the Signals” page.

7. Instruct students to write a paragraph explaining why pizza is or is not a good “brain food.” OR have students address the question, Would you eat pizza for breakfast before an important test?

8. Encourage students to share answers within their groups and then let each group present to the class.

Extensions

• Encourage students to create or find recipes that include many nutrients needed by the brain. Share these with the class OR have a “Brain Food Day,” during which students (or parents) bring different foods to share in class, or prepare one or more of the students’ recipes in class.

• Have students use an online Calorie counter or App to investigate the caloric, fat and nutrient content of common fast foods.

Handouts and Downloads