Do non-caloric sugar substitutes promote weight gain?
Non-caloric sugar substitutes that flavor diet sodas and reduced-calorie foods—like saccharin, aspartame, sucralose and stevia—are the subject of intense, ongoing debate. Critics point to trends of increasing consumption of these sweeteners that mirror increasing rates of obesity, suggesting that the former may be responsible for the latter. Others contend that replacing higher-calorie, sugar-sweetened foods and drinks with diet versions by definition will result in weight loss if all other dietary factors are held constant.
To complicate matters, there is scientific evidence that supports both of these arguments. In other words, we simply do not know whether drinking, say, diet soda versus regular soda, definitively promotes weight gain, weight loss—or neither.
Sugar substitutes are 180-13,000x sweeter than sugar, and some research suggests that regular exposure to these products modifies taste preferences toward more intensely-sweet flavors. Also, because this sweet taste is not accompanied by the calories (energy) our brain expects it to be, the complex systems our bodies have to regulate energy balance may be thrown off kilter. The result is that a diet high in artificial sweeteners may possibly, over time, cause people to seek out more calories from other sources in order to satisfy the cravings that sweet—but calorically empty– foods create. But can we say that your individual diet soda habit will make you fat? Based on available science, we cannot.
While most Americans consume these non-caloric sugar substitutes in some form or another, it appears that they’re here to stay. But because these sweeteners tend to be found in highly-processed foods that we’d all benefit from cutting down on, my recommendation is to focus the bulk of your diet on fresh, minimally-processed foods like fruits, vegetables, whole grains, beans, nuts, low-fat dairy, fish and small portions of lean meat—and keep the sweet-tasting foods and drinks—regardless of how they’re sweetened– to a minimum.
Tamara Duker Freuman RD