Diet Sodas Linked to Obesity
A recent scientific study showed that fat people drink more diet soda than thin people.
Just when you thought the news about losing weight couldn’t get any worse, try this: A review of 26 years of patient data found that people who drink diet soft drinks were more likely to become overweight. Not only that, but the more diet sodas they drank, the higher their risk of later becoming overweight or obese – 65 percent more likely for each diet drink per day.
The findings, the latest from the long-term San Antonio Heart Study, took even the researchers by surprise. “I was baffled,” said Sharon Fowler, a faculty associate at the University of Texas Health Science Center, who presented the data Saturday at the American Diabetes Association’s 65th Annual Scientific Sessions in San Diego, Calif.
Researchers looked at questionnaires and medical records for 1,177 patients who began enrolling in the study in 1979. All had weights considered either normal or overweight, but not obese. The volunteers were asked how many soft drinks per day they usually drank and whether they were regular or diet – or a combination of each. The researchers followed up with them over the years.
Drinking any soda – regular or diet – was linked to a higher risk of becoming overweight. But when the researchers adjusted the data to account for differences in age, sex and ethnicity, they found that regular soft drinks had very little connection with serious weight gain. Diet drinks, however, did.
The researchers are quick to point out that their findings are not proof that drinking diet soft drinks causes people to become heavy. It could be that as they began gaining weight, they switched from regular to diet drinks.
No kidding. I’m guessing they would find similar results for low fat ice cream, Snackwells, low carb pizza, and other products bearing the Atkins, South Beach Diet, and Weight Watchers labels. The number of purportedly scientific medical studies relying on simple correlation, which would get a freshman political science student a D-minus, continues to astound me.
John Hawkins notes the old Social Science 101 teaching point of noting that ice cream sales and incidences of rape are positively correlated. The instructor eventually gets the student to realize that the correlation is spurious and that a third variable, in this case “heat,” is correlated to both. A more direct example is that ice cream sales and drownings are related, also because both increase during hot weather. Thus, freshmen social scientists learn immediately that correlation does not equal causality. Surely, medical researchers know that, too.