Clifford S. Mintz Ph.D., author of Bio Job Blog, writes about a study suggesting that artificial sweeteners may cause people to gain rather than lose weight. Like Cliff, I had heard reports of this but never paid much attention. Although the study was published several months ago, I recently became interested in it because I am trying to kick a bad dependence on diet sodas.
Over the past few years, I have heard rumors that artificial sweeteners like saccharine, aspartame and sucralose actually cause people to gain rather than lose weight. I summarily dismissed these stories because they did not make sense to me nor did I think that they had any scientific merit-until today!
Purdue University psychologists Drs. Susan Swithers and Terry Davidson fed rats yoghurt sweetened with glucose (15 calories per teaspoon) or yoghurt containing the artificial sweetener saccharin (0 calories per teaspoon). Rats that were fed the saccharin-sweeten yoghurt subsequently consumed more calories, gained more weight, put on more body fat and were unable to regulate dietary intake of calories as compared with rats that were fed glucose-sweetened yoghurt. The authors surmised that breaking the connection between a sweet sensation and high-calorie food, changes the body’s ability to regulate caloric intake. This could partly explain why obesity has risen with the increasing use of artificial sweeteners in drinks. The study’s findings are consistent with emerging evidence that people who drink more diet drinks are at higher risk for obesity and development of the metabolic syndrome that increases the risk for heart disease and diabetes.
So, how do the authors explain their seemingly paradoxical findings? Swithers and Davidson postulate that ingestion of sugar-rich (sweet) foods provides a ‘salient orosensory stimulus” that signals that the body is about ingest a lot of calories. This, in turn, induces the body to physiologically-prepare itself for ingestion of a high calorie meal. However, when the false sense of sweetness (provided by the artificial sweetener) is not followed by consumption of large amounts of calories, the system gets “confused”- causing people to eat more or expend less energy to account for the calorie imbalance. Nevertheless, the good news is that people who use artificial sweeteners can still count calories to regulate caloric intake and body weight. Unfortunately, as the authors suggest, counting calories requires a more conscious effort and a lot more work than routinely consuming low-calorie foods.
Although this study was conducted in rats, its findings are consistent with the observations that increased use of artificial sweeteners can contribute to human weight gain. Despite the study’s findings, similar experiments must be conducted in people to substantiate or refute the authors’ hypothesis.
More about Cliff Mintz: Cliff has an extensive background in biopharmaceutical training and science career development. He has been a management consultant to a number of emerging and publicly-traded biopharmaceutical companies. Cliff has also held a variety of positions including stints as a medical school professor, professional recruiter, and medical/science writer.
(All excerpts used with permission.)