Losing weight is easier when there is money on the line, U.S. researchers said on Tuesday. They said weight-loss programs that award people with money—and remind them of the cash they【M1】______ stand to lose if they fail—provided with a powerful incentive to【M2】______ lose weight compared with more conventional approaches. Dr. Kevin Volpp of the University of Pennsylvania School of Medicine was looking for an effective way to treat obese, a growing problem【M3】______ that carries serious health risks. He said many weight-loss programs fail before people are being asked to make sacrifices【M4】______ now. Volpp and colleagues studied two kinds of incentive programs for weight loss. One was a lottery-based design in which participants played a lottery and were allowed to collect their winnings if they met their weight-loss target. The other was a deposit contract, in which participants invested small amount of【M5】______ their own money which they would lose at the end of the month if they succeeded to reach their goals. People in this group also got a【M6】______ bonus if they met their goal. The researchers resigned 57 obese but otherwise healthy【M7】______ people to one of these two groups or a control group, in which people were simply weighed at the end of each month. All were aimed to lose 7.26 kg by the end of four months. People in the【M8】______ incentive groups lost far more weight than that who got no pay for【M9】______ their efforts, with about half of the participants in each group meet【M10】______ their weight loss goals. 【M1】