You won't have any trouble getting your students interested in this unit since food is an important part of their lives. Adolescents are particularly fascinated with their changing bodies and that interest can certainly be exploited when studying nutrition and the biology of the digestive system.
The unit begins with a focus on the composition of food and, therefore, on nutrition. From the outset, the students are dealing with relevant topics, such as junk foods, fat, carbo-loading, and calories, that relate directly to their health and their performance. By studying their own diets in terms of composition and calories, they will immediately be applying the science they are learning to their eating habits and the choices they make each day.
A feature of this unit that I particularly like is the imaginary trip through the digestive system. I think this is a creative and memorable way to teach students both anatomy and physiology. If you can augment the images created by doing an actual dissection, students will never forget this unit.
The activities in this unit are particularly rich and they generate many links to other disciplines. For example, the activity that calculates and models the total surface area of the small intestine is a link to mathematics. The activity that measures the composition of foods is a link to chemistry. And, the activity that measures the caloric content of a peanut is a link to physics. One activity that is just plain fun, and students love, is the peristalsis activity.
The connections to health are a really important aspect of this unit. On one hand, we are a nation that runs on fast foods and junk foods, is pathologically overweight, and suffers an incredibly high incidence of eating disorders. On the other hand, health food stores are everywhere, grocery stores commonly carry foods that are “organic,” and more of our population exercises regularly and eats healthy diets than ever before. Low fat and low cholesterol are probably the most common words on food labels these days. Thus, young people are receiving conflicting messages about foods and eating habits. They must make choices, and those choices will have long-lasting effects on their health. What they learn in this unit will help them make informed choices and hopefully the right choices more often than not. Also, with the activities in this unit on diet analysis, evaluation of menus, and interpretation of food labels, it is likely that discussions of these activities will extend from the classroom to the home. In one test-site school, the parents became so involved that they made it possible to have ethnic meals for the class, with the recipes fully evaluated for dietary components, of course.
Best wishes and bon appétit!
H. Craig Heller
Chair, Department of Biological Sciences, Stanford University