2014届最新高考英语一轮单元复习 精品阅读理解提升文章精选一百篇（84）
Unit 84 Liposuction's Limits Doctors have long suspected that excess fat around the belly -- as opposed to the thighs or hips -- increases the chances of developing heart disease, high blood pressure and diabetes. Apparently, belly fat doesn't just lie there and jiggle. It actively promotes ill health by, among other things, pumping out inflammatory proteins and interfering with the body's ability to use insulin. So it seemed plausible to many physicians that surgically removing belly by liposuction could give patients a double benefit: a slimmer figure and a better metabolic profile.
That's why there was such disappointment with the news, reported in the New England Journal of Medicine last week, that unlike losing weight the old-fashioned way -- by eating less and moving more -- liposuction makes no difference in a person's biological risk factors. Researchers in St. Louis, Mo., and Rome, Italy, conducted extensive tests on 15 obese women before and three months after they underwent liposuction. "We removed 20 to 22 pounds of fat from each patient," says Dr. Samuel Kline, director of the Center Human Nutrition at Washington University in St. Louis. That's twice as much fat as is usually removed. The women were instructed not to diet or exercise more until the experiment was over. All reported that they felt better and could move more easily after surgery. But with respect to their metabolic risk factors, Klein says, "The data after the procedure were identical to the data before the procedure." How is that possible? Liposuction does not remove the fat cells found in the liver or the muscles, or the so-called visceral fat that surrounds internal organs. Nor does liposuction reduce the size of any remaining fat cells; large fat cells appear to produce more harmful proteins than do small ones. Some doctors believe the results would have been better if the patients had been only a few pounds overweight. In any case, the best way to shrink fat cells is still to create a negative energy balance by -- you guessed it -- eating fewer calories than you burn. Disappointing as this study might be, there is still hope for folks who struggle with their weight. It is becoming increasingly clear that even modest weight loss -- of as little as 5% -- can lead to real improvements in your health. The more weight you lose -- and keep off -- the better. But you don't have to get all the way back to normal weight. Most of us will never see a model-slim figure in the mirror. But we can all lead healthier lives.