UConn researchers are finding that applying the concept of reinforcement can be an effective way to improve efforts to lose weight.
“The importance of maintaining a healthy body weight is clear to most, but the pervasiveness of obesity in our population today suggests that that’s not motivation enough, or at least not enough to keep people motivated to lose weight,” says lead author Nancy Petry, director of the Behavioral Cardiovascular Prevention Program in the Pat and Jim Calhoun Cardiology Center.
The contingency management approach attempts to steer patients toward making healthy choices by rewarding those choices. Petry, who has received millions of dollars in grants for her research on the treatment of addictive disorders, has demonstrated the effectiveness of contingency management, a behavioral intervention that uses reinforcers, in treating addictions such as drug abuse.
In a study published in The American Journal of Medicine, Petry, Dr. William White and Danielle Barry from the Calhoun Cardiology Center, and Linda Pescatello from the Kinesiology and Human Performance Laboratory in Storrs used reinforcement techniques on half the participants. All participants were considered overweight or obese based on their body mass index, a ratio of weight to height.
All participants received supportive counseling, but those assigned to the reinforcement group also were eligible for prizes if they met certain weight-loss goals. For example, a patient who lost at least a pound in a given week would draw from a prize bowl. The prize bowl contained 500 cards, 250 of which were prizes. Most of the prizes were valued at around $1, and some were of greater value, offering a chance at larger prizes such as an iPod or fitness equipment. The average cost per draw was approximately $2.
At the end of the 12-week study, the results showed an average weight loss of 6 percent of body weight in the reinforcement group, compared to an average body weight loss of 3.5 percent in the counseling-only group. Almost two thirds of those in the reinforcement group lost at least 5 percent of their baseline body weight, compared to a quarter of those in the counseling-only group.
“The difference is significant in terms of weight loss, and with it, improvements in cholesterol and heart rate,” says White, professor of medicine and chief of the Calhoun Cardiology Center Division of Hypertension and Clinical Pharmacology. “This study demonstrates that with modest expense we can improve the success of those trying to lose weight.”
The average person in the reinforcement group earned less than $14 per week in prizes.
“From a behavioral economics standpoint, what makes this a particularly attractive intervention is the fact that the benefits of weight loss, and the associated reduction of health risks like diabetes, heart disease and stroke, far outweigh the expense of the prizes,” Petry says.
The researchers concede that their data only demonstrate short-term weight-loss enhancement and that a longer and larger-scale evaluation is warranted, but they also conclude, “to achieve long-term benefits, one first needs to achieve initial success.”