BSCS Biology: A Molecular Approach

Unit 1: Energy, Matter, and Organization

The Nutrition Of Carbohydrates

Introduction
How often do you think about what is in the food you eat? Whether you fuel your body with a slice of pepperoni pizza or carrot sticks, your food is made up of just 3 nutritional building blocks: carbohydrates, proteins, and fats. Of these, scientists consider carbohydrates to be the body's primary fuel.

Research has shown that the kinds of carbohydrates we eat can dramatically impact our health. Scientists divide carbohydrates into two groups: simple and complex. Nutritionists often categorize carbohydrates by their glycemic index. What is the glycemic index? How do simple carbohydrates differ from complex carbohydrates? Why are some carbohydrates better for you than others? What kinds of carbohydrates should you be eating for good health? Understanding this information is critical if you want to make informed decisions about the food you consume.

Task
Your job in this WebQuest is to learn about the different kinds of carbohydrates that make up food. You will learn how your health can be affected by the kinds of carbohydrates you eat. You will learn about the glycemic index method of categorizing carbohydrates. You will learn what fiber is and what role it plays in your diet. You will learn about the dangers of eating too much sugar. You will discover how Americans are doing at meeting the government's guidelines for carbohydrates consumption. You will answer a set of questions about carbohydrates to demonstrate what you have learned in your Internet research.

Time
1-2 class periods for research and answering the set of questions.

Process
First, read the following set of questions before you begin your Internet research. As you explore each site, look for answers to the questions.

Questions about the Nutrition of Carbohydrates

Describe the difference between a simple carbohydrate and a complex carbohydrate. What foods are sources of simple carbohydrates? What foods are sources of complex carbohydrates?
Scientists now classify carbohydrates by their glycemic index. What is glycemic index? Why do nutritionists consider foods with low glycemic index to be better for you?
Fiber has no nutritional value, yet it is very good for us. What is fiber? Why is eating fiber healthy? What are some foods that are high in fiber?
Most American children consume too much sugar. The average 4 or 5 year old consumes 17 teaspoons, about 1/3 of a cup, of sugar daily. What is the largest source of added sugar in the diet of American children? What are some of the health risks of eating too much sugar?
According to the Federal government's Dietary Guidelines for Americans, what percentage of your daily grain servings should be made up of whole grains? What percentage of whole grains, on average, are Americans actually eating?
How many daily fruit and vegetable servings does the Dietary Guidelines for Americans recommend? On average, how much are Americans eating? What vegetables are Americans overconsuming, and are these vegetables high glycemic or low glycemic foods?

Resources
http://home.howstuffworks.com/food2.htm

Visit this Web site to read about how carbohydrates work as fuels in the body. Read a description of the various kinds of carbohydrates.

http://www.americanheart.org/presenter.jhtml?identifier=4471

Visit this site from the American Heart Association to read about the different kinds of carbohydrates. Learn what kinds of foods are sources of simple carbohydrates and complex carbohydrates.

http://www.hsph.harvard.edu/nutritionsource/carbohydrates.html

Go to this site from the Harvard School of Public Health for an explanation of the different kinds of carbohydrates and the glycemic index.

http://www.caloriesperhour.com/faqs_fiber.html

Visit this site to learn about fiber and why it is important.

http://www.nutritiondata.com/nutrient-search.html

Go to this site to search for foods that are high or low in fiber, sugars, and other nutrients.

http://www.cancer.org/docroot/PED/ped_3.asp?sitearea=PED

Go to this American Cancer Society site to read about the connection between diet and cancer. Click on "The Link Between Lifestyle and Cancer" and scroll down to the section titled "Controlling Weight" to read about the link between diet and cancer.

http://kidshealth.org/parent/nutrition_fit/nutrition/sugar.html

Visit this site and read about the different kinds of carbohydrates. Learn which carbohydrates are healthiest. Scroll down to read about "good" versus "bad" carbs and the health consequences of too much sugar.

http://www.ucsfhealth.org/childrens/health_library/reuters/2005/01/20050117elin013.html

Go to this site to read about research from Penn State University showing the effect of too much sugar in children's diets.

http://www.ers.usda.gov/Amberwaves/April05/Features/FruitAndVegChoices.htm

Go to this site from the USDA to read about how Americans are doing on eating their fruits and vegetables.

http://www.ers.usda.gov/Amberwaves/April05/Findings/WholeGrainConsumption.htm

Visit this USDA site and read an article about American's whole grain eating habits.

Conclusion
In the process of completing the Internet research on nutrition, you have become informed about the importance of carbohydrates in the diet. You have learned how the kinds of carbohydrates you eat can impact your health. You have learned about the health benefits of eating a diet that is high in fiber and low in sugar. You have learned about the Federal government's recommended daily levels of fruits, vegetables, and whole grains. You have discovered how well Americans are doing, on average, with meeting these recommendations. Next time you choose a food to eat, look at the nutrition label. What kinds of carbohydrates are in your food?