A response to this connection has been to advocate for artificial sweeteners, sugar substitutes that advertise the sweet flavoring without the health drawbacks of regular sugar. However, the correlation between sweeteners and obesity doesn’t seem to be disappearing at all. In fact, even as the American public consumes significantly more sweeteners, the waistbands still seem to be getting bigger. An exhaustive 9-year study by the University of Texas showed that of over 5,000 San Antonio adults, there was still a link between obesity and sweeteners. This link can be shown in the consumption of diet sodas, which claim to have eliminated calories by using artificial sweeteners in the soda rather than sugar. Consumers of diet sodas, in another study, showed links between the artificially sweetened beverage and heart-disease, obesity, and type-2 diabetes.
The difficulty in proving the inefficacy of sweeteners in controlling these health drawbacks is that individuals that consume sweeteners are often the same people that consumer other unhealthy foods that could be linked to similar health problems. In that way it’s hard to prove correlation, so researchers tend to depend on the trends within data, which shows that sweeteners are every bit as unhealthy as sugars if over-consumed. In fact, they may be worse because sweeteners advertise that they are the healthy alternative to sugars, and may give people the illusion that they can be consumed in higher quantities.
Susan Swithers of Purdue University attempted to answer this question in 2008 by conducting a study in which rats were fed yogurt with glucose, a simple sugar, or saccharine sweetener. The result was that rats fed saccharine yogurt put on more body fat and consumed extra calories, and even showed that rats that ate saccharine continued to gain more even after the study was over. The result, as Swithers explained to Wired.com, was that the rats bodies may have switched into a calorie-saving mode when they didn’t get the caloric “rush” they expected from consuming sugars. As a result, their bodies stored more fat than they otherwise would, which may explain the correlation in weight gain and fat production.