A 16-week, Internet-delivered program produced a reduction in BMI z-score in adolescent boys and girls, which was not sustained in the four months following the intervention. Upon examining the data, the intervention group maintained their weight during the intervention, which is encouraging considering that adolescents can “outgrow” their overweight if they maintain weight and continue to increase in height [31
], as they did in the current sample. In comparison, adolescents who received usual care, consisting of educational handouts on nutrition and physical activity, also reduced their BMI z-scores, but to a lesser degree. ED attitudes and behaviors were generally reduced in both groups, with slight, but not clinically significant, increases in dietary restraint (at post) and shape concerns (at follow-up) in the intervention group. These findings suggest that a minimally intensive and easily disseminable program is modestly effective for weight control in the short term and that ED risk factors were not significantly impacted either positively or negatively. These findings may have implications for the early intervention of OW without negative impact on ED risk.
The weight loss reported in this study is much less than that reported in adult studies [15
]. However, the weight change from baseline to post was comparable to or better than that found in an evaluation of an Internet weight control program for African American adolescent females (e.g., +5.29 lbs control group; +1.21 lbs intervention) [33
]. Adolescents may possess lower levels of self-efficacy or motivation to lose weight compared with adults. Parental involvement was limited in this study and it may be helpful to increase the support and motivation provided by parents in assisting adolescents with weight control. For instance, it may be beneficial to develop a parallel Internet program instructing parents on changing the home environment and providing instrumental support for their adolescents' behavioral changes (e.g., helping obtain a gym membership), as has been found in previous programs [19
]. Specifically targeting parents for weight control, as well, may be an important way to increase family-wide behavioral changes for weight control [34
Overall, the hypothesis that the intervention would reduce ED behaviors and attitudes compared to the control group was not supported. In fact, participants appeared to decrease ED symptoms in both groups, with the exception of dietary restraint. Dietary restraint can be defined as cognitive and/or behavioral efforts to limit food intake for shape or weight reasons. An example of this would be avoiding certain foods that one likes in an effort to change one's weight/shape or going for long periods of time without eating (e.g., 8 hours or more) in order to influence one's weight/shape. The intervention group reported increased dietary restraint from BL to post, which is likely due to adherence to program recommendations, rather than a reflection of increased ED attitudes or behaviors; indeed, the SB2
group's mean scores on the Restraint subscale were commensurate with healthy young adolescent girls [35
] and OW adults [36
]. Shape concerns were reduced in both groups, but to a greater degree in the control group. It is possible that the increased focus on weight control in the intervention group moderated the downward shift on this measure compared with the control group. In addition, to explore the possibility that different versions of the EDE-Q may have impacted these findings, the primary analyses were run separately for the EDE-Q and the youth version of the EDE-Q. The differences between the intervention and control groups on ED variables were no longer found, thus, differences between groups on shape concerns and dietary restraint may have been a product of using different versions of the EDE-Q.
Alternatively, it is possible that the lack of improvement in the SB2
group on ED variables was due to the limited exposure to the relevant materials in the intervention. Adherence with the intervention was surprisingly low, with one-third of participants accessing <10% of the program. Yet, low adherence with Internet-delivered programs for weight loss in youth has been seen in other studies [37
]. This highlights the importance of identifying ways to increase adherence when using Internet-delivered programs with youth. Further, the ED related materials were presented during weeks 8-16 and this relatively late introduction may have come at a time when adherence was decreasing. In contrast, satisfaction was quite high, suggesting that Internet interventions are appealing to adolescents and that additional reminders through innovative means (e.g., cell phone text messaging) or incentives to use the program could improve adherence and outcome. An analysis of the effective components of the program could aid in reducing the overall number of program expectations, thus improving adherence as well.
The SB2 group reported greater use of eating- and PA-related weight-loss skills at post and 4-month FU, such as self-monitoring calorie intake and the use of problem-solving skills to be more physically active, than the control group. This finding reflects skills taught in the intervention and suggests that the SB2 group adopted and maintained important, healthy lifestyle changes. Although the reduction in OW was modest, these behavior changes could translate into future weight control.
Limitations of the current study include a small sample size and lack of longer-term follow-up. Also, these findings may not apply to adolescent populations with less comfort with and/or access to the Internet. The strengths of the current study include a randomized design incorporating a usual care group to represent what most OW adolescents might routinely receive in the community. The study's sample was ethnically diverse, with half of the sample identifying themselves as Black, Hispanic, or “other”, representing an important contribution given that most studies of pediatric obesity treatments have been conducted with a largely White population [38
]. The current findings provide preliminary support for the feasibility of Internet-delivered weight control in reducing overweight status in adolescents.