Obesity prevention in defined (high school) populations.

Background: A challenge for the widespread dissemination of Internet-based programs designed to produce weight maintenance/loss in defined (high school) populations is to adapt them to local needs and interests, whereas demonstrating effectiveness and salience for both universal and targeted populations.

Objective: The objective of this study is to examine the feasibility of providing an inexpensive, Internet-based universal (healthy weight regulation) and targeted (weight maintenance/loss) health program to all ninth-grade students in a high school serving a lower socioecnomic status, diverse population.

Design: A total of 118 normal-weight and 64 overweight/obese students in the same ninth-grade class completed a baseline screen and were allocated to a healthy weight regulation program or a weight-loss maintenance program. Both groups simultaneously received a 10-week Internet-based intervention. Program implementation required minimal teacher time. Measurement included self-reported fruit, vegetable and high-fat/-calorie food consumption, self-reported change in body mass index (BMI), weight and shape concerns, as well as program engagement.

Results: The program was successfully implemented in nine classes, with minimal help from the investigators. There was a significant increase in self-reported consumption of fruits and vegetables (P=0.001). There was a significant reduction in self-reported BMI in the overweight/obese group (P=0.001). Students found the program helpful and engaging. There was a significant reduction in weight and shape concerns in the high-risk female students, consistent with a reduced risk for the development of an eating disorder. Providing a universal and targeted online healthy weight regulation program to ninth-grade students is feasible and inexpensive. The results suggest the program can serve as 'core' for future studies using adaptive, continuous quality-improvement designs.