Obesity Culprit or Scapegoat?
The American Beverage Association (ABA) argues that sodas are taking too much of the blame for obesity.
“A calorie is a calorie, and what the data clearly show is that Americans are eating too much and taking in too many calories, period,” says Maureen Storey, PhD, the ABA's senior vice president of science policy.
Not everyone agrees with that. Sugary soft drinks, in particular, have been shown in many studies to be associated with overweight and obesity, as in a review of 30 studies published in 2006 by researchers from the Harvard School of Public Health. Many of the studies included in that review showed that overweight children and adults drink more sugary beverages than normal-weight kids and adults, and several studies found that the more sugar-sweetened drinks people drank the greater their likelihood of becoming overweight.
At the time, the ABA criticized the review, claiming in a news release that the Harvard researchers “chose to ignore critical articles and studies that contradicted their hypothesis,” such as a 2005 study finding no link between soda and obesity in Canadian children.
Yale University researchers also examined the obesity issue, combing through 88 studies.
They found that people tend to eat more calories on days when they drink a lot of sugar-sweetened drinks, and that soda drinkers tend to be heavier than people who don't drink soft drinks.
The researchers hypothesized that the body does not easily recognize calories derived from beverages, so people end up eating more. But the Yale study wasn't designed to prove that.
As for diet sodas, nutrition researcher David L. Katz, MD, who directs the Yale Prevention Research Center, told WebMD in November 2010 that the research as a whole suggests sugar substitutes and other non-nutritive food substitutes have little impact on weight. “For every study that shows there could be a benefit or harm, there’s another that shows no ‘there’ there,” Katz says.
Patterns of Bias?
The ABA says the vast majority of studies supporting a soda-obesity link were done by researchers with strong anti-soda biases. Storey also says many of these biased or poorly done studies are covered by news media, while studies showing no link don't get the same attention.