Bubble Bursts for Childhood Obesity Prevention Program

BOURNEMOUTH, England, Oct 9-A campaign to urge kids to stop drinking sugared carbonated beverages-an effort to have them lose weight or prevent obesity-didn’t seem to have much value in the long run, reported investigators here.

Although children enrolled in an obesity prevention program had a modest reduction in body mass index compared with controls at 1 year, 2 years later the difference had vanished, and the prevalence of obesity was the same in both groups, reported Janet James, RN, of Royal Bournemouth Hospital, and colleagues.

“The original project provided hope that a simple intervention could be beneficial in preventing obesity, but our new results show no effect 2 years after the end of the intervention,” they wrote online in BMJ.

The project, known as the Christchurch obesity prevention program in schools, or CHOPPS, targeted carbonated beverages, high in refined sugars but bereft of nutritional value, as a major contributor to childhood obesity and overweight.

A total of 644 elementary school students from the ages of 7 to 11 were enrolled in the 1-year intervention, in which children were randomized to a control group or to an intervention group. The latter consisted of a “ditch the fizz” campaign urging kids to forgo sodas and to attend four 1-hour sessions, teaching them the benefits of a healthy diet, spread throughout the school year.

At 1 year, there was a 7.5% increase in the percentage of overweight and obese children in the control group, and a decrease of 0.2% (mean difference 7.7%, 2.2% to 13.1%), the authors reported in BMJ in 2004.

“A school-based educational program aimed at reducing the consumption of carbonated drinks to prevent excessive weight gain in children ages 7 to 11 years was effective,” they wrote at that time.

In the current study, conducted 3 years after baseline, the authors tracked down 434 members of the original cohort and conducted anthropometric measures to see whether the between-group differences had been maintained.

They measured the children’s height, weight, and waist circumference, and converted BMI and waist circumference measures to z scores corrected for age and sex. They also converted BMI measures to percentile values with growth reference curves.

They found that at 3 years after baseline BMI, z scores had increased in the control group by 0.10 + 0.53, but decreased in the intervention group by -0.01 + 0.58, with a mean difference of 0.10 (95% confidence interval, -0.00 to 0.21, P=.06).

In both the control and the intervention groups, the prevalence of overweight increased, and the differences between the groups the investigators had seen at 1 year had disappeared.

Among the controls, the mean BMI increased by 2.14 + 1.64, and in the intervention group, it increased by 1.88 + 1.71, with a mean difference of 0.26 (95% CI, -0.07 to 0.58; P=.12).

The waist circumference also increased in both groups after 3 years, with a mean difference of 0.09 (95% CI, -0.06 to 0.26; P=.25).

“It remains unclear whether specific interventions or those that focus on all aspects of the diet and physical activity are the most successful,” the authors wrote. “Perhaps the true impact of any school-based intervention can effectively be evaluated only if the interventions are continuous.”

They noted that about one-third of the original cohort was lost to follow-up, and that financial and time limitations prevented them from collecting data on changes in carbonated beverage consumption or the socioeconomic and pubertal status of the children.