WASHINGTON -- As the obesity epidemic among youths and its associated risks for later health problems -- heart disease, diabetes II and some cancers - grow, health researchers are finding that many current programs aimed at preventing unhealthy weight gain fall short. And, those programs that are successful only work for short periods of time.
What can work? Brief, targeted interventions that focus on weight loss only, according to a review of the research. These findings are reported in the September issue of Psychological Bulletin, published by the American Psychological Association (APA).
Psychologists from the University of Texas at Austin conducted a meta-analysis of the last 25 years of research that examined 64 programs in 46 studies to determine which programs were the best at preventing weight gain in children and adolescents. It is estimated that 70 percent of obese adolescents will stay overweight as adults if they don't shed the weight in their younger years, and interventions must begin early to prevent later health problems, said lead author Eric Stice, PhD, and co-authors Heather Shaw, PhD, and C. Nathan Marti, PhD.
The intervention programs examined in the meta-analysis varied in duration, whether parents were involved, the type of content provided, dietary and activity instruction, number of behaviors targeted and types of instructors and delivery (lecture versus interactive).
Interventions that simultaneously attempted to change many health factors, such as body weight, blood pressure, cholesterol and smoking, were less effective at preventing weight gain than interventions that focused solely on body weight, said Stice. Interventions that targeted children and adolescents compared with preadolescents and those targeting females versus males were also more effective. Furthermore, the reviewers found that prevention programs tended to produce larger effects when delivered by professionals rather than schoolteachers.
In the 46 studies reviewed, 51 programs (79 percent) had no effect on preventing weight gain. The 13 programs (21 percent) that did prevent weight gain used intensive regimens, said the authors. On average, these programs had 40 hours of intervention time that ranged from 3-120 hours. Only three intervention programs (5 percent) kept the participants from gaining weight beyond the 3 year follow up period.
According to the findings of the meta-analysis, most of the interventions failed at preventing weight gain among the youths, and the ones that were successful had only short-term benefits lasting only three years. More research is needed to build on the existing programs that were effective in stopping weight gain, said Stice. "Programs for preadolescents and males will require new approaches because these two populations derived the least benefit from the existing programs."
"Understanding the barriers to adapting healthier lifestyles will also help improve the obesity prevention programs," said Stice. "Research has shown that certain internal factors, such as lack of will power and/or perceptions that a person is too busy to change his/her diet or find time to exercise may play into the high failure rates of the current obesity prevention efforts."
Article: "A Meta-Analytic Review of Obesity Prevention Programs for Children and Adolescents: The Skinny on Interventions that Work," Eric Stice, PhD, Heather Shaw, PhD, and C. Nathan Marti, PhD, University of Texas at Austin, Psychological Bulletin, Vol. 132, No.5.
Eric Stice, PhD can be reached by phone at (541) 484-2123 or by e-mail.
The American Psychological Association (APA), in Washington, DC, is the largest scientific and professional organization representing psychology in the United States and is the world's largest association of psychologists. APA's membership includes more than 150,000 researchers, educators, clinicians, consultants and students. Through its divisions in 54 subfields of psychology and affiliations with 60 state, territorial and Canadian provincial associations, APA works to advance psychology as a science, as a profession and as a means of promoting health, education and human welfare.