Skip to main content

16-11-2011 | Psychology | Article

Web-based intervention ineffective for modifying BMI, physical activity


Free abstract

MedWire News: Study findings show that a web-based computer-tailored intervention has positive short-term effects on eating behaviors in adolescents, but is not associated with improved long-term outcomes in body mass index (BMI), waist circumference, or physical activity.

"The results of our study seem to be in line with the findings of recent reviews that have indicated that classroom-based educational programs (not only computer tailored) seem to be effective for promoting dietary intake but not for promoting physical activity," say Nicole Ezendam (Tilburg University, the Netherlands) and co-authors.

The team measured self-reported behaviors (diet, physical activity, and sedentary behavior) and pedometer counts at baseline and 4 months after administration of the FATaintPHAT web-based intervention or no intervention in 883 students aged 12-13 years from 20 schools in the Netherlands. BMI, waist circumference, and fitness were measured at baseline and after 2 years.

The intervention consisted of eight separate modules aimed to address weight management and energy balance-related behaviors. Participants were allocated 15 minutes for each lesson over a 10-week period.

Regression analyses showed that the intervention had no effect on BMI, waist circumference, and the percentage of students who were overweight or obese.

At 4 months' follow-up, individuals in the intervention group were 46% less likely to report drinking more than 400 mL of sugar-sweetened drinks per day compared with controls (odds ratio [OR]=0.54, 64.3 vs 75.8%). Mean self-reported snack consumption was also significantly lower among adolescents in the intervention group at 4 months (4.9 vs 5.5 pieces per day). However, these differences were no longer significant at the 2-year follow-up.

The researchers also found that students assigned to the intervention group reported eating significantly more pieces of fruit and consuming more grams of vegetables per day at 4 months compared with controls (1.74 vs 1.58 pieces per day, and 118 vs 99 g/day, respectively).

Among students at risk, those in the intervention group were less likely to report participating in sports at the 4-month follow-up than controls (OR=0.45, 66.5 vs 82.3%).

Furthermore, fewer steps per week were recorded at 4-month follow-up among at-risk individuals assigned to the intervention compared with controls, although this trend reversed at 2-year follow-up (71,007 vs 82,672, and 71,923 vs 59,534, respectively).

The researchers say that the lack of significant changes at the 2-year follow-up suggests that the intervention may not have been intensive enough to have sustained effects, possibly owing to its short duration.

"Expanding the intervention with additional components or booster sessions might improve the effectiveness in the short and long term," conclude the researchers in the Archives of Pediatric and Adolescent Medicine.

By Ingrid Grasmo

Related topics