C. Look back at the reading to find the answers to these “Why?” questions.

DISCUSSION

Discuss the following questions in pairs or groups.

1. Are there foods that you like now that you didn’t like when you were younger? Are there foods that you don’t like now that you liked when you were younger? Explain.

2. What are some foods that grow in your area? What are some foods that are imported? Where do the imported foods come from?

3. What foods have recently become popular where you live? Have you tried them?

6. WARM UP

Which of these food groups should you eat the most of? Which should you eat the least of? Number the food groups from 1 (the most) to 6 (the least). Share your answers with your classmates.

whole grains

meat, fish, and poultry

fruit

dairy products, such as milk and yogurt

sweets, such as cake and cookies

vegetables

DISCUSSION

1. Do you think there is a relationship between the foods you eat and your health?

2. Do you usually read food labels? Why or why not?

3. What do you think the reading is going to be about?

8. VOCABULARY PREVIEW

A Read the word lists. Put a check (✓) next to the words that you know and can use in a sentence. Compare your answers with a partner. Then look up any unfamiliar words in a dictionary.

B. Fill in the blanks with words.

1. The … of humans has increased because of modern medicine.

2. The mouse is the most common ….

3. He is trying to lose weight, so he is counting every ….

4. A healthy … includes a lot of fruit and vegetables.

5. Losing weight takes a long time. It is a slow ….

6. Scientists analyze the … from their experiments.

7. People with red hair have a … that makes their hair red.

8. Young people usually … more candy than older people.

9. In some religions, people do not eat anything on certain days. They ….

10. They did a lot of exercise and ate less. Their health improved a lot. It improved ….

11. There is a health … to eating lots of fruits and vegetables.

12. Many parents … the amount of sugar their children eat.

9. READING

Read the story.

Eat Less, Live Longer?

Owen and Canto live near each other. They lead similar lives and are close in age, but they look very different. Canto is strong and healthy. Owen, on the other hand, is slow and heavy. He is losing his hair, and he moves like an old man.

The biggest difference between Owen and Canto, however, is their life expectancy. Scientists expect Canto to live 30 percent longer than Owen. Why? Every day for 17 years, Canto has eaten a diet with many fewer calories than Owen. Scientists think this is the reason Canto does not have heart disease or diabetes, common health problems in old age. It seems that eating less has kept Canto’s body younger.

Owen and Canto are not people – they are monkeys. They live in a scientific research laboratory at the University of Wisconsin in the United States. Scientists at the lab are studying the effects of low-calorie diets. Does eating a diet with many fewer calories in it have health benefits? Does eating less also increase life expectancy?

Scientists in other laboratories around the world are doing similar research. So far, the results suggest the same thing. If you restrict the number of calories that an animal eats, it will live longer than an animal that eats a lot. In one study, mice ate 30 percent fewer calories than normal. These mice lived 40 percent longer than the mice that had a normal diet. They also had fewer age-related problems and diseases.

Scientists are beginning to understand the reason for the benefits of eating less. When the body gets less food, the body produces a substance called sirtuin. This substance acts on the genes in the body that control aging. Sirtuin seems to slow down the aging process.

Humans, of course, are not lab animals. Will a very low-calorie diet give humans the same health benefits as lab animals? Scientists are beginning to study the effects of calorie restriction on humans, too. In one study, scientists studied two groups of people for three years. In the first group, people ate a normal diet. They consumed between 2,000 and 3,500 calories a day. In the second group, people ate a healthy, low-calorie diet. They consumed only 1,000 to 2,000 calories a day. After three years, the people in the second group were significantly healthier. They had lowered their risk of diabetes and heart disease.

Will eating fewer calories lead to a greater life expectancy for humans? It will take scientists much longer to find this out. Humans live much longer than laboratory animals, such as mice and monkeys.

There is a group of people, however, who already believe they will live longer by eating less. They are members of the Calorie Restriction Society. They have studied the data about animals. They believe that restricting their calories will increase their life expectancy and help them live healthier lives. On some days, they fast, and they rarely eat more than 2,000 calories a day.

Scientists don’t expect many people to follow such an extreme diet. They also don’t expect a huge increase in human life expectancy. Many scientists expect an increase of about 9 percent, but others expect only 2 percent. They believe the major benefit of a low-calorie diet is a healthier, more active life, as Canto the monkey has. A 90-year-old may feel like a 65-year-old.

We are still waiting for scientists to tell us if calorie restriction really works. So, the best advice is to eat well. Just don’t eat too much!

READING CHECK