Do Diet Sodas Make You Fat? A University of Texas Study Seems to Say So


Do not drink?

It was too good to be true — the idea that you could drink massive amounts of diet soda and suffer no ill consequences. The New York Post reports today on a University of Texas medical school study that shows that people who drink diet sodas are 70 percent more likely to suffer an increase in waist size — an average of two inches over the course of the 10-year study — than those who don’t.

The study results were showcased at the annual meeting of the American Diabetes Association in San Diego. The experimental group included those who drank two or more 12-ounce diet sodas per day. “The promotion of diet sodas and artificial sweeteners may be ill-advised,” said Helen Hazuda, one of the study’s authors.

Indeed, other scientific studies have shown negative consequences for mammalian users of artificial sweeteners. Another one at the University of Texas showed that mice fed aspartame demonstrated a regular increase in blood-sugar levels, an early harbinger of diabetes. It seems that artificial sweeteners send metabolic signals to the brain that can also lead to lower insulin levels in the blood.

An earlier University of Miami study showed an increase in heart attack and stroke risk following use of artificial sweeteners.

But don’t throw away your Diet Cokes just yet. These are all correlation studies that make sensational news, but may not be great science. For example, is it possible the experimental group in the first University of Texas study may have been growing fat already, or even been inadvertently selected for their propensity for pudginess? The sample size on these studies is often laughably small, and, until the metabolic mechanism for these phenomena have been established, it’s wise to look at them with some skepticism.