TCS Daily

Kicking the Can

By John Luik - July 8, 2005 12:00 AM

Blame it on the Terminator. Ever since California Governor Arnold Schwarzenegger mused that he wanted to extend California's school junk food ban to school vending machines by replacing "junk food", including soft drinks, with milk and vegetables, there has been a race among the food police in other states to see who can come up with the most draconian restrictions on what kids can eat at school. So far the prize goes to Connecticut whose lawmakers recently passed legislation (latter vetoed by Governor Jodi Rell) that would ban the sale of soda pop and junk food in all school cafeterias, vending machines and stores. In a session that lasted longer than debates on the death penalty and same-sex civil unions, legislators argued that such bans were a necessary part of the fight against childhood obesity. Similar measures, though not as extensive, are currently on the legislative calendar in 17 other states.

From the growing hysteria about soft drinks and so-called junk foods -- so-called because there seems to be no clear and non arbitrary rationale for why certain foods are labeled "junk" -- in schools you would think that the problem of childhood obesity was caused primarily by the snack foods and pop that kids buy and eat at school. Though such claims have been made for a number of years by the food fanatics at the misnamed Center for Science in the Public Interest, they began to gain credibility after a 2001 study by David Ludwig which claimed that soda consumption is a major risk factor for childhood obesity. Escalating the rhetoric over the soda pop issue was a study last year by two Harvard high priests of the obesity=death faith, JoAnn Manson and Walter Willett, who claimed that there was a link between soft drink consumption and Type 2 diabetes in women. Willett went so far as to suggest that the message of the study was "Anyone who cares about their health or the health of their family would not consume these beverages."

Unfortunately, while the soda pop bans for schools and the posturing of Willett might be good politics, it is bad science. Consider the results of a just published survey involving 137,000 children in 34 countries from researchers at the Health Behavior in School-Aged Children Obesity Working Group (published in Obesity Reviews). The research was designed to look at overweight and obesity in school aged children and to examine whether there was a connection between being overweight and diet and physical activity. What the researchers found was that in "91% of the countries examined, the frequency of sweets intake was lower in overweight than normal weight youth." Even more importantly the researchers found that there was a "negative relationship between the intake of sweets (candy, chocolate) and BMI classification in 31 out of the 34 countries.. such that higher sweets intake was associated with a lower odds of overweight." In other words the children who eat larger amounts of so-called junk food, actually had less chance of being overweight. Again, "Overweight status was not associated with the intake of fruits, vegetables, and soft drinks..." Statistically significant relationships were found between physical activity and lower weight and more time spent watching television and a greater risk for being overweight.

This research follows several recent studies that have also found that soda pop and junk food do not cause childhood obesity. For example, a recent study in the International Journal of Obesity by six Harvard researchers that looked at the eating and physical activity habits of 14,000 US children aged 9-14 over a three year period found that junk food does not lead to obesity among children. However snack food was defined, with or without soft drinks, the researchers were unable to find a link between these foods and obesity. As the authors note, the "inclusion of sugar-sweetened beverages in the snack food category did not meaningfully change the results. Regardless of the definition of snack foods, there was not a strong association between intake of snack foods and weight gain." Moreover, the overweight and obese children in the study were not eating more snack foods than the thin children.

The Harvard study confirmed an earlier one in the International Journal of Food Sciences and Nutrition that found no correlation between children's weight and soda consumption. These findings also echo those of two previous studies from last year that looked at the alleged junk food/pop/obesity connection. One, from scientists at Penn State, found "no statistically significant relationship between the percentage of calories from ice cream, baked good, candy and chips and BMI [Body Mass Index] scores for adolescent girls." The other, from researchers at the University of California that examined diet, sedentary behavior and physical activity in adolescents, found that the only risk factor for increased BMI was lack of physical activity. As they noted, "Of the 7 dietary and physical activity variables examined in this cross-sectional study, insufficient vigorous physical activity was the only risk factor for higher body mass index for adolescent boys and girls." Some researchers have found, for instance, that between 25 and 40% of children and adolescents are inactive during their leisure time, with less than a quarter of adolescents receiving a day or more a week of PE at school.

The link between increased weights and declining amounts of physical activity has been reported elsewhere, though it seldom receives more than passing mention from the obesity activists who prefer to make soft drinks and "junk food" their target. It also makes sense in light of what we know about children's food consumption over the last two decades. Lisa Sutherland from the University of North Carolina, for example, in looking at government nutrition data, found that from 1980-2000, adolescent caloric intake increased by only one percent. As Dr. Mark McClellan, former FDA Commissioner noted: ".... In a debate that has often focused on foods alone, actual levels of caloric intake among the young haven't appreciably changed over the last twenty years."

All of this is unlikely to divert the fat fanatics who see children and soda pop as a way to begin their interventionist crusade. Speaking of soft drink bans in schools, Harold Goldstein, director of the California Center for Public Health Advocacy, sees them as "just the entry point to address the bigger issues." But the real science on this issue suggests that soft drinks do not cause obesity: that it if we are to kick anything it should be the couch, not the can. If we really want to do something to help our children, rather than taking something like pop out of schools we should instead by putting something like physical activity back into them.

The author is writing a book about health policy.


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