Your body needs energy, protein, minerals, vitamins and fibre. In order to get all of these it is important to have a varied and balanced diet, and to eat the right amount. Your bode 'burns' food to get energy. The amount of energy provided by food is measured in units called calories.
           How many calories do you need? This depends on your weight and on what you do. When you are asleep, your body uses nearly one calorie an hour for every kilogram of weight. So a person who weighs seventy kilos uses about 560 calories while sleeping for eight hours; in other words, he needs about 1680 calories just to stay alive for 24 hours, even without doing anything. More calories are needed for different activities - from 100 calories an hour for reading or watching TV, to 350 calries an hour for playing football. To calculate the number of calories needed per day for an average person, first find out that person's ideal weight. (Your ideal weight is what you should weigh. It depends on your height and your build, and it may be very different from your present weight!) Then multiply (nhân) the correct weight (in kilograms) by 40 for a woman or 46 for a man. A 57-kilo woman may need about 2300 calories a day - more if she does heavy physical work or a lot of sport, less if she is very inactive.
           If you eat more than you need, the extra calories turn into fat; if you eat less than you need, the body burns fat to get energy and you lose weight. One way of losing weight is by dieting - eating less. Another way is to go on eating the same amount, but to increase your body's need for energy by taking more exercise. But be careful. It is important to slim - or to start an exercise programme - gradually. Don't try to lose a lot of weight fast. It doesn't usually work and it can be dangerous.
1. According to the passage, a 49-kilo woman needs about......
    A. 1,720 calories a day
    B. 1,760 calories a day 
    C. 1,960 calories a day
    D. 2,960 calories a day
2. A blanced diet means..............
    A. One with the quantity and variety of food needed for good health
    B. One with exact portions of food
    C. One with no fat at all
    D. One that helps you to lose weight
3. The word 'inactive' in live 14 most nearly means............
    A. unable
    B. thin
    C. unhappy
    D. idle
4. The writer advised us to lose weight by................
    A. eating as little as possible
    B. eating no protein, minerals, vitamins and fibre at all
    C. getting all the fat out of our body
    D. having no extra calories
5. Another way of losing weight is............
    A. exercising
    B. doing a lot of homework
    C. taking as much exercise as possible
    D. starting an intensive exercise programme