问答题

Just about everyone has been on a (47)______ at one time or another, and millions of us have learned that the weight we lose is all too easily regained. Still few people question the wisdom of dieting. After all, we reason, the worst that can happen is that we’’ll regain the weight we’’ve lost—then we can simply go on a diet again. But some new research suggests there is a risk: yo-yo dieting may seriously (48)______ the body’’s weight-control system. The more diets you go on, the harder it may become to lose weight. Ever worse, new (49)______ indicates that repeated (50)______ of losing and gaining weight may raise the risk of heart problem. This last possibility is especially (51)______. As part of a 25-year study that (52)______ 1959 men, researchers reported mat the men showing large up-and-down weight changes had twice the risk of heart disease as those with only small changes in weight. One paper from the Framingham Heart Study, which has monitored more than 5000 people for 40 years, also provides troubling information: people who lose ten percent of their body weight had about 20 percent (53)______ in risk of heart disease—but people who gained 150 to 135 pounds, and back to 150 again, could leave you with a higher heart-disease risk man you started with. None of this means that dieting is (54)______ or foolish. For those who are 20 percent or more overweight, mere are good reasons to reduce: successful weight loss can (55)______ blood pressure, help control blood sugar in diabetics(糖尿病患者) and enable people to feel better about themselves. But the new research does suggest that dieting must be taken seriously by people at any weight. It also means dieting alone is not the best way to weight control. When a weight-loss program includes exercise, you lose more fat and less muscle, and you’’re not likely to gain the weight back. That’’s because exercise may help resist the (56)______ changes that tend to come from yo-yo dieting. Word Bank A) concept B) reduction C) theory D) diet E) disturbing F) ineffective G) overall H) evidence I) physical J) monitored K) predict L) distort M) accurate N) lower O) cycles