A provocative study recently appeared in the journal Behavioral Science*  suggesting that artificial sweeteners may actually promote weight gain rather than weight loss. 

The study involved giving 27 male rats yogurt that was sweetened with either glucose or saccharin.  The researchers reported that the rats consuming the artificially sweetened yogurt consumed more calories, and body weight and adiposity increased in that group.

In attempting to interpret the findings, the researchers hypothesized that the sweet taste of food prepares the system to respond in a certain way, and when the sweetness is not accompanied by calories, the body becomes confused.  This then leads to metabolic slowdown and to increased weight gain.  They stated, “…it is conceivable that just as exposure to non-predictive sweet taste-calorie relationships in the laboratory appears to promote increased body weight and body adiposity in rats, the widespread use of non-calorie sweeteners in the food environment of humans may have similar effects on the predictive validity of sweet tastes and ultimately on the normal ability of humans to control their intake and body weight.”

Of course, the Calorie Control Council, a trade group for low and reduced calorie beverages and foods, disagrees that there could be any relationship. This group has also continued to deny for many years that there are any potential adverse health effects from consuming artificial sweeteners as well.

I’ll be the first to acknowledge the limitations of this study.  It involves rats, not people, and the researchers could not arrive at any firm conclusions.  However, I’ll use any opportunity to advise people against using artificial sweeteners.  Aside from mountains of evidence about their potential to damage health, they are ineffective as a weight loss tool, since they do not address the cause of excess weight – the overall American diet that focuses on calorie-rich foods rather than calorie-dilute, high-fiber, densely nutritious foods.  Many people continue to consume some version of the Standard American Diet with the addition of artificial sweeteners, rather than undertaking the total dietary overhaul needed to lose weight and improve health permanently.  This study is just one more reason to discard this mentality.

*Swithers, S.E., Davidson, T.L., “A Role for Sweet Taste: Calorie Predicitive Relations in Energy Regulation by Rats,” Behavioral Science Feb 2008 vol 122, No 1, doi:10.1037/0735-7044.00.0.000