Unit 2 Healthy eating健康饮食

must的用法

1）表示主观的义务和必要, 主要用于肯定句和疑问句, 意思为 “必须……，得……，要……”；由must 引起的疑问句，肯定回答要用must或have to, 否定回答要用needn?t或don?t have to, 意思是“不必” ； must的否定形式mustn?t表示禁止，意思是“不能，不许”。如： — Must I finish the task right now? 我现在必须完成这个工作吗？

—Yes, you must. / Yes, you have to. 是的。

(—No, you needn?t. / No, you don?t have to. 不，不必。) You mustn?t come here without permission. 未经允许，你不能来这儿。 have to 的用法

1）must表示一种主观的需要，而have to 表示一种客观的需要，意思是“不得不”。 如：

I have to attend an important meeting this afternoon. 今天下午我不得不参加一个重要的会议。 Mother is out, so I have to look after the shop. 妈妈不在家，因此我不得不照看商店。

2）have to 的否定形式是don?t have to, 相当于needn?t。如： They don?t have to buy a computer at present. 他们目前没有必要买电脑。 背景知识

I．Healthy Eating for Lifetime Variety, Balance and Moderation

A healthy diet includes all foods. Variety is important because no one food can

provide all the nutrients the body needs for health. Try new foods to tantalize your taste and vary your nutrient intake.

We can make many possible choices within each food group. Choices may be

made to accentuate specific needs like fiber. For example, in the protein-rich ?meat?

group, beans are a low fat, high fiber option compared to ground beef. In the fruit group, whole fruit is usually a higher fiber choice than fruit juice.

Foods containing important nutrients can help us prevent disease and even restore

our health. Striking a balance between foods that promote health and those that may be risky is important for long term well being. Choose foods that are better for your health more often.

Without a doubt, fats and cholesterol are the single most important group of

nutrients to limit in your diet if you want to reduce your risk of chronic disease. Heart disease and cancer, two of this nation?s leading killers, are linked to diets high in fat. Other chronic health problems may be exacerbated by high fat diets. Saturated fat, that is, fat that is solid at room temperature, appears to carry the greatest amount of risk.

Alcohol is not pictured on the food pyramid, but if it were it would be in the tip of

the pyramid. Alcohol has only empty calories in the way that sugar and most fats do. Pregnant women should avoid alcohol beverages.

Foods and beverages that are less nutritious do not have to be eliminated but they

should be consumed in moderation - saved for special occasions. Making healthy food choices can be the difference between health and disease. II. 10 Tips to Healthy Eating

Experts agree the key to healthy eating is the time-tested advice of balance,

variety and moderation. In short, that means eating a wide variety of foods without getting too many calories or too much of any one nutrient. These 10 tips can help you follow that advice while still enjoying the foods you eat.

1. Eat a variety of nutrient-rich foods. You need more than 40 different nutrients for good health, and no single food supplies them all. Your daily food selection should include bread and other whole-grain products, fruits, vegetables, dairy product and meat, poultry, fish and other protein foods. How much you should eat depends on your calorie needs. Use the Food Guide Pyramid and the Nutrition Facts panel on food labels as handy references.

2. Enjoy plenty of whole grains, fruits and vegetables. Surveys show most Americans

don?t eat enough of these foods. Do you eat 6-11 servings from the bread, rice, cereal and pasta group, 3 of which should be whole grains? Do you eat 2-4 servings of fruit and 3-5 servings of vegetables? If you don?t enjoy some of these at first, give them another chance. Look through cookbooks for tasty ways to prepare unfamiliar foods. 3. Maintain a healthy weight. The weight that?s right for you depends on many factors including your sex, height, age and heredity. Excess body fat increases your chances for high blood pressure, heart disease, stroke, diabetes, some types of cancer and other illnesses. But being too thin can increase your risk for osteoporosis, menstrual irregularities and other health problems. If you?re constantly losing and regaining weight, a registered dietitian can help you develop sensible eating habits for successful weight management. Regular exercise is also important to maintaining a healthy weight.

4. Eat moderate portions. If you keep portion sizes reasonable, it?s easier to eat the foods you want and stay healthy. Did you know the recommended serving of cooked meat is 3 ounces, similar in size to a deck of playing cards? A medium piece of fruit is 1 serving and a cup of pasta equals 2 servings. A pint of ice-cream contains 4 servings. Refer to the Food Guide Pyramid for information on recommended serving sizes. 5. Eat regular meals. Skipping meals can lead to out-of-control hunger, often resulting in overeating. When you?re very hungry, it?s also tempting to forget about good nutrition. Snacking between meals can help curb hunger, but don?t eat so much that your snack becomes an entire meal.

6. Reduce, don?t eliminate certain foods. Most people eat for pleasure as well as nutrition. If your favorite foods are high in fat, salt or sugar, the key is moderating how much of these foods you eat and how often you eat them.

Identify major sources of these ingredients in your diet and make changes if necessary. Adults who eat high-fat meats or whole-milk dairy products at every meal are probably eating too much fat. Use the Nutrition Facts panel on the food label to help balance your choices.

Choosing skim or low-fat dairy products and lean cuts of meat such as flank steak and beef round can reduce fat intake significantly.

If you love fried chicken, however, you don?t have to give it up. Just eat it less of ten. When dining out, share it with a friend, ask for a take-home bag or a smaller portion. 7. Balance your food choices overtime. Not every food has to be “perfect”. When eating a food high in fat, salt or sugar, select other foods that are low in these ingredients. If you miss out on any food group one day, make up for it the next. Your food choices over several days should fit together into a healthy pattern.

8. Know your diet pitfalls. To improve your eating habits, you first have to know what?s wrong with them. Write down everything you eat for three days. Then check your list according to the rest of these tips. Do you add a lot of butter, creamy sauces or salad dressings? Rather than eliminating these foods, just cut back your portions. Are you getting enough fruits and vegetables? If not, you may be missing out on vital nutrients.

9. Make changes gradually. Just as there are no “super foods” or easy answers to a healthy diet, don?t expect to totally revamp your eating habits overnight. Changing too much, too fast can get in the way of success. Begin to remedy excesses or deficiencies with modest changes that can add up to positive, lifelong eating habits. For instance, if you don?t like the taste of skim milk, try low-fat. Eventually you may find you slimming, too.

10. Remember, foods are not good or bad. Select foods based on your total eating patterns, not whether any individual food is “good” or “bad.” Don?t feel guilty if you love foods such as apple pie, potato chips, candy bars or ice-cream. Eat them in moderation, and choose other foods to provide the balance and variety that are vital to good health. Figuring Out Fat

With so much information available about the effects of dietary fat on health,

understanding the role fat plays in a well-balanced diet can be pretty confusing. To cut through the confusion, it?s important to remember that fat is an essential nutrient that everyone needs to stay healthy.

Fat is a valuable energy source and carries fat-soluble vitamins needed for proper

growth and development. It also contributes important taste and textural qualities that