Am Fam Physician. 2009;79(7):602-603
Background: More than one third of adolescents are overweight or obese. Binge eating is associated with excess weight and increased weight gain. Targeting binge eating may help adolescents stabilize their weight. Binge eating involves a loss of control over eating, which leads to objective or subjective binge episodes. It is often accompanied by psychological symptoms, including body image concerns and depression. Weight loss studies have not focused on the effects of cognitive behavior therapy for binge eating and weight loss in adolescents. Jones and colleagues examined the effect of an Internet-based intervention on reducing binge eating in adolescents at risk of overweight and obesity.
The Study: Of the 105 high school students who enrolled in the study, 52 were assigned to the intervention and 53 to the wait-list control group. Participants were included if they had a body mass index (BMI) greater than or equal to the 85th percentile for their age group, and had exhibited binge eating behaviors at least once per week in the preceding three months. However, students were excluded if they had anorexia or bulimia. Participants were also required to have access to the Internet.
Eligibility was assessed during a baseline telephone interview. Participants then completed a self-report questionnaire and a semi-structured diagnostic interview for a formal evaluation of their eating behavior. Their heights and weights were measured, and they were assessed for objective and subjective binge-eating episodes, as well as for objective overeating episodes not associated with loss of control. A 21-item diet inventory assessed participants' dietary sugar and fat intake. Participants were also assessed for depression using a 20-item depression scale.
The intervention consisted of a 16-week Internet-based program (StudentBodies-2-BED [SB2-BED]) designed to help users implement cognitive behavior techniques to control weight, including self-monitoring, goal setting, stimulus control, appetite awareness, and emotion regulation skills. The program addressed healthy eating, weight and binge eating management, and physical activity. It also included a facilitated asynchronous online discussion group. In addition to the four-month post-treatment follow-up, participants were reassessed for height and weight measurements nine months after the baseline assessment.
Results: Of the 18 participants lost to follow-up, eight were in the intervention group and 10 were in the control group. In the intervention group, 31 percent of participants never logged on to the Internet program; the remaining SB2-BED participants used some component of the program. In an intention-to-treat analysis of the final 44 intervention students and the 43 control students, the intervention group experienced significantly greater reductions in BMI z score (t103 = −3.15; P < .01) and change in BMI (t103 = −2.58; P < .01). At baseline, 7 percent of participants (n = 3) in the intervention group and 5 percent in the control group (n = 2) were not at risk of overweight. These percentages increased to 27 and 12 percent, respectively, at follow-up. There were significant reductions in subjective and objective binge-eating episodes in the intervention group. These reductions were identified in the baseline to post-treatment period and in the baseline to follow-up period.
There were significant decreases in weight and shape concerns in the SB2-BED group; however, these decreases did not occur in the intention-to-treat analysis. No differences between groups were noted in changes in objective overeating episodes, dietary fat and sugar intake, or depression. Measures of physical activity were unreliable because of variation among participants and inaccurate scores. When correlated with baseline disordered eating, BMI z scores improved in the intervention group compared with the control group regardless of whether there was disordered eating at baseline.
Conclusion: This study showed improvements in weight maintenance and binge eating in high school students using a self-directed online educational program, despite low adherence rates. Although an Internet-based self-help tool may not achieve the same benefit as face-to-face interventions, it is an effective, low-cost option in adolescent weight management. Because the highest degree of participation occurred in the early weeks of the program, a front-loaded intervention with “booster” sessions might make future programs more effective.