It’s like an ongoing bad joke, ordering a diet soft drink with your super-extra-value-sized fast food meal in order to be ‘healthy’. But whether people do it out of conviction that diet sodas are somehow better than regular soft drinks, flavor preference, or an aspartame habit, few people really believe diet soft drinks are the answer to weight loss. Still, the industry keeps trying. Their latest attempt: a study funded by the American Beverage Association suggests diet soft drinks are even better than water when it comes to losing weight.
The report, published in the journal Obesity, found that dieters who were given the option of drinking diet soda lost more weight than a group that could only drink water. Proof that diet sodas are the answer to the obesity problem!? Not so fast. Not only was the study paid for by those with a vested interest, it also falls far short of being a scientifically sound analysis.
Over a three month period, 300 people took part in the study. Those who were allowed to drink diet sodas lost, on average, about 13 pounds. Those who were only allowed water lost 9, a difference of 4 pounds.
John Peters, one of the study authors, says they were surprised by the findings. He remarks that some of the people in the diet soda group reported less hunger, but emphasizes this is just speculation.
“I’m kind of amazed how much people are trying to find a reason not to believe these findings,” said peters, surprised at the backlash the study is receiving. People are understandably skeptical of the findings because the research was funded by the ABA.
(Here are 11 ways to boost metabolism and lose weight).
“This paper is fatally flawed, and leaves us with little science to build on,” says researcher Susie Swithers of Purdue University. Swithers points out that the paper doesn’t discuss what the participants were eating, what they swapped out in exchange for the diet soda beyond the water they were required to drink. Further, the limited length of the study means we have no idea how long dieters were able to keep up the weight loss differences.
On another note, researchers from Purdue reviewed a dozen studies all published within the last five years on the health risks of consuming diet soda. They published their findings in an opinion piece in Trends in Endocrinology & Metabolism (pdf); it was there they revealed their “shock” over their findings.
While Peters and the ABA may be shocked at the general skepticism, a 2007 study in PLoS Medicine found that ‘industry funding’ dramatically increases the odds that a study will favor the industry’s position on a topic, regardless of the protocols in place to keep bias out.