The Journal of the American Medical Association has recently published a study regarding the best incentives that can convince the obese to keep on with their weight-loss programs. Experts from University of Pennsylvania School of Medicine, who carried out the research, concluded that the ones fighting the war against the pounds are best motivated if there is a money reward on the line or if they fear losing some money, too.

The scientists studied the behavior of 57 participants, who were targeted to lose about 16 pounds (around 7 kilos) in four months. The subjects of the study were divided into three distinct groups. One of them was the control group, which was only given the assignment of losing the requested number of pounds, and whose members were only weighed at the end of each month.

For the other two groups, Dr. Kevin Volpp, the leading expert, said that different measures were to be taken. "We wanted to create a reward system which gave them rewards in the present," he stated. As a result, one of the groups participated to a lottery-like type of program. They were playing the lottery each day, and they were being told exactly how much money they would gain if they reached the weight targets. If the results were satisfactory, they were allowed to take the money won at the lottery.

The other group put under the lens by the specialists was part of some sort of investment program – each day, they were asked to invest a small sum of money, from 1 cent to $3 , that would be lost if they did not stick to the weight aimed by the specialists. They were also receiving compensations if reaching the goal.

At the end of the stated four months, the researchers discovered that the ones losing more weight were the people in the investing group, about 14 pounds, followed by those “winning” the lottery, who were “lighter” by 13 pounds. The people in the control group proved to be the laziest, as they only got rid of around 4 pounds.

"There is a very strong sense of loss aversion," observes Dr. Volpp, who believes that the only good reasons that people can find for fighting obesity are the material ones. He is also skeptical about the long-term efficiency of such a method.