Obesity generally is defined as an accumulation of fat beyond what is considered normal for a person’s age, sex, and body type. In today’s society obesity is considered a disease, not a moral failing. It occurs when energy intake exceeds the amount of energy expended over time. Only in a small minority of cases is obesity caused by such illnesses as hypothyroidism, or the result of taking medications, such as steroids , that can cause weight gain.
　　

The more a person weighs, the more blood vessels the body needs to circulate blood throughout the body. The heart takes on a heavy burden as it has to pump harder to force the blood flow through so many vessels. As a result, the heart grows in size and blood pressure tends to rise. Obesity is also a factor in osteoarthritis (because of the extra weight placed on the joints), bone and joint diseases, respiratory ailments, gallbladder disease, complications during pregnancy and delivery, and higher accidental death rate.
　　

Obesity can alter hormone levels, affect immune function, and cause impotence in men and reproductive problems in women. Women who are 30% overweight are twice as likely to die of endometrial cancer, and those who are 40% overweight have four times the risk. Obese women also are more likely to incur cancers of the breast, ovaries, and gallbladder. Obese men are more likely to develop cancers of the rectum, colon, bladder, pancreas, stomach, and prostate.
　　

Obesity can also cause psychological problems. Sufferers are associated with laziness, failure, or inadequate willpower. As a result, overweight men and women blame themselves for being heavy, thus causing feelings of guilt and depression.
　　

Scientific evidence has found an association between BMI (body-mass index) and higher death rates. However, the relative risk of being heavy declines with age. Some researchers have found that data linking overweight and death are inconclusive, while other researchers have found that losing weight may be riskier than dangers posed by extra pounds. Some researchers counter that overweight indirectly contributes to over 300,000 deaths a year.
　　

A poll by Shape Up America found that 78% of overweight or obese adults have abandoned dieting as a means of losing weight. Diets do not teach people how to eat properly. They merely restrict food intake temporarily, so when the diet ends, weight gain resumes.
　　

1. Which of the following expresses the main idea of this passage?
　　A) Obesity puts a burden on the heart.
　　B) Many people are constantly dieting.
　　C) Obesity is considered to be a disease.
　　D) Obesity can lead to many serious health problems.
　　

2. According to the passage, _____.
　　A) obesity is often related to medications such as steroids
　　B) obesity does not affect a person’s chance of getting cancer
　　C) a diagnosis of obesity is based on a normal weight for one’s age and sex
　　D) obesity is becoming less of a problem in today’s society
　　

3. According to the passage, why does dieting not result in permanent weight loss?
　　A) Diets don’t teach people good eating habits.
　　B) Diets lead to people’s guilt and depression.
　　C) There are too many diets and each has different requirements.
　　D) Diets cause feeling of deprivation.
　　

4. Which of the following is implied in Paragraph 5?
　　A) Losing a lot of weight is not wise for older people.
　　B) Some surgical methods for weight loss are better than dieting.
　　C) All obese people need to shed their extra pounds.
　　D) Obese people should consult their doctors about the pros and cons of losing weight.
　　

5. Which of the following can be concluded from this passage?
　　A) Obesity is not a major health risk.
　　B) Scientists agree on the connection between obesity and death.
　　C) Obese people are likely to be biased against by others.
　　D) Obese people often blame others for their conditions.

（提示：10月7日《每日一练》答案C,B,D,C,A)