Junkfood Science: Stepford kids

May 17, 2007

Stepford kids

Once again, when the media gives an inordinate amount of attention to a study, it’s usually a good clue that something other than exemplary science may be at work. Only interests selling a weight loss program would consider under a single pound after one year and several million dollars, to be evidence of success.

Nationwide, the news has been reporting on the entire town that went on a diet, all to conquer childhood obesity, and that the program was a success. After years of talk about an “obesigenic” environment and excuses that the reason no childhood obesity prevention program has ever worked was because the entire environment needed to change, this massive project set out to do just that. Every conceivable facet of society in an entire town of 77,500 people was changed to focus on diet and exercise.

The Associated Press story reported:

City goes on a diet — and it worked

More fruits and vegetables were added to school lunches. Restaurants offered smaller portions. Crosswalks even got a fresh coat of paint to encourage walking and biking. The whole city of Somerville went on a diet to curb childhood obesity. And ...public schoolchildren in this Boston suburb avoided gaining about a pound of excess weight compared with their 8-year-old counterparts in two nearby communities.

With the launch of the “Shape Up Somerville” project, a special task force organized every exercise, sports, healthy eating and weight management program in town to focus adults and kids on losing weight. No one would be able to escape it. It would take a village to get kids slim, they resolved.

The school food service was revamped, food service staff were trained on nutrition, vegetarian recipes were developed, fresh fruits and vegetables became daily standards at every meal, diet educational messages covered school walls and cafeterias, vending machines and classroom snacks were made healthy, and even school teachers were instructed to be good role models. The school curriculum was focused on “healthy eating” with over 90 specially-trained teachers giving lessons on four themes: eating more fruits, vegetables, whole grains and low-fat dairy foods; decreasing fats and sugars, increasing exercise and decreasing television viewing. Exercise was incorporated into the classroom hours and PE mandated. After school programs were developed on healthy cooking and physical activity, and each one had a field trip to an organic farm. Parents and adults in the community received outreach education, regular educational newsletters and coupons for healthy foods. Community events and media were devoted to the diet and exercise message. Restaurants got involved with “Shape Up Approved” menu items. City planners gave the entire community a face lift to facilitate walking and biking and safe routes to school; nice sidewalks and biking paths were built, crosswalks repainted, traffic lights were designed to encourage safety, bike racks were installed, and open spaces were created. School nurses and all of the area pediatricians were especially trained to monitor and intervene on childhood overweight.

The Somerville Physical Activity Guide instructed residents to get active and every community resource was tasked towards that goal: city parks, playgrounds, after school programs, child care and youth programs, teen centers, toddler programs, special needs gyms, camps, the circus, senior centers, fitness clubs and gyms, wellness centers, prenatal programs, exercise classes, softball and little league, basketball leagues, bicycle tours and clubs, bowling leagues, dance and music lessons and studios, football and cheerleading leagues, community gardens and gardening clubs, gymnastics classes, skating and hockey rinks and classes, martial arts and yoga centers, Oriental academies, boy scouts and eagle scouts, girl scouts and rainbow programs, running clubs, soccer leagues and camps, swimming lessons and water aerobics at community pools, family swim programs, pee wee tennis instructions, volleyball leagues, walking clubs for kids to elderly, countless nutritional classes and weight management programs.

The project was funded with a $1.5 million grant from the U.S. Centers for Disease Control and Prevention; and grants from Robert Wood Johnson Foundation, Blue Cross Blue Shields, United Way, the U.S. Potato Board, Dole Food Company and Stoneyfield Farms. There was a lot at stake in showing this role model initiative would work.

The results were just published in Obesity, the journal of the North American Association for the Study of Obesity. It reported that the growing children in the program had gained less weight than children in two control groups in nearby communities. The difference in BMI was 0.1005.

The Tufts University researchers concluded:

In the intervention community, BMI z-score decreased by –0.1005 (p = 0.001, 95% confidence interval, –0.1151 to –0.0859) compared with children in the control communities after controlling for baseline covariates....this study effectively decreased BMI z-score in a group of high-risk children through a community-based environmental change intervention. These results are significant given the obesigenic environmental backdrop against which the intervention occurred. This model demonstrates promise for communities throughout the country confronted with escalating childhood obesity rates.

But two major flaws in this study defuse such optimistic conclusions: the duration and weight loss measures.

As we know, obesity experts and the scientific evidence have resoundly noted that no weight loss program can be evaluated until it demonstrates weight loss for at least five years. Declaring any program a success after such a short time period of one school year is without merit. It’s even less tenable with growing children because they naturally fluctuate in BMI percentiles as they go through growth spurts, making any determinations of obese or overweight inappropriate and premature without a period of watchful waiting.

While 0.1005 points of BMI might seem significant to these researchers, it is every bit as tiny as it sounds — under one pound after a year. But it is also important to recognize that it’s a “calculated intervention effect:” it was not an actual weight loss in the children, but the amount calculated that the growing children didn’t gain as a result of this initiative. It was based on comparing the Somerville children in the program with those in two nearby communities — but those were very different children. The groups were not evenly matched. The Somerville group had more whites and Asians, whereas significantly more blacks and hispanic children were in the control groups. The control groups also had higher percentages of single, unmarried mothers and the Somerville kids had more highly-educated parents, with 4 to 5 times more parents with graduate school educations, reflective of higher socioeconomic status.

It is glaring that the researchers reported results only in terms of overall BMIs and didn’t break down the numbers of children who were underweight, at risk for overweight, and overweight at the end of the program. How many of these children, immersed in such an extremely weight-obsessed environment, had developed eating disorders? Had there been an increase in the numbers who were underweight, as we saw in Arkansas? It is worrisome that the Somerville girls showed more of an “intervention effect” than the boys, which points to more body weight concerns and dieting behaviors among them. Ages 8 to 9 is a period of naturally rapid growth for girls as they enter pre-puberty. Plotting the girls’ overall heights and weights on the CDC growth curve, which pediatricians use to watch that healthy children are growing appropriately, the nonintervention girls stayed right on the growth curve. The intervention group, however, slightly fell off the growth curve during the year-long program. While small, there is no evidence that such a change is healthful, especially if it continues.

Did the program actually reduce rates of overweight or obese? The researchers were mysteriously quiet about that, too. No doubt if they’d been able to show a “significant” impact on reducing the numbers of fat children, they would be shouting those results from the rooftops.

While this massive program, which they hope to replicate across the country, was focused on weight, there was no attempt to determine if it made a lick of difference in the school children’s health. Parents and the public might also ask if these incredible resources could have been directed in areas that might have a greater importance in bettering the children’s futures. While the school year was absorbed in diet and exercise, (after the Shape Up program was completed in 2005) the average reading test scores among Somerville kids are 15.4% below state average, and their math test scores are a whopping 26% below those of kids in the rest of the state.

But, heh, they’re a little thinner and I guess that’s all that counts.

© 2007 Sandy Szwarc

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