Jeffrey T. Kullgren, MD, from the Veterans Affairs Ann Arbor Healthcare System, Michigan, and team recruited 105 employees of Children's Hospital of Philadelphia who were obese with body mass index between 30 and 40 and were eager to lose weight. The participants aged between 18 and 70 years old.
The participants were randomly assigned to one of following three groups, group financial incentives, individual financial incentives, or controls. They were given access to Weight-Control Information Network website of the National Institute of Diabetes and Digestive and Kidney Diseases to refer to diet and exercise suggestions.
The weight and behavior of the participants were monitored on a monthly basis for six months. The participants were required to lose 0.4 kg every week. Participants in the individual financial incentives group who met the weight loss target received $100 a month. In the group financial incentives group, each group was assigned $500 and that the amount was shared among the members of the group who attained the weight loss goal. The control group received no incentives.
At the end of the study, it was found that people with group incentives had lost more weight, an average of 4.8kg, while people with individual incentives had lost an average 1.7kg. People in the group had lost only 0.5kg.
According to the authors, the competitiveness and a chance to win more than $100 had motivated the participants in the group incentives to reduce weight more efficiently.
The researchers indicate that now different group based approaches need to be compared to figure out the most efficient techniques. This could help save health care cost for the employers and employees may benefit from improved health.
The findings are published in the Annals of Medicine.