In a taste of good news for dieters this holiday season, a recent research review finds that sugar substitutes may not promote eating more calories or packing on extra pounds.
The existing body of research on artificial sweeteners is a bit of a mixed bag. Some studies have linked sugar substitutes - especially in diet drinks - to increased appetite or changes in the way the body handles sugar. But other research has tied the products to successful weight loss.
For the current analysis, researchers examined data from 79 previously published papers on human consumption of sugar substitutes such as aspartame (NutraSweet), saccharin (Sweet'N Low), stevia (Truvia) and sucralose (Splenda).
Using these sweeteners instead of real sugar can lead to reduced calorie intake and lower body weight, the researchers conclude in the International Journal of Obesity.
"Consuming low-energy sweeteners instead of sugar reduces both energy intake and body weight," lead study author Paul Rogers, a psychology researcher at the University of Bristol in the U.K., said by email. "Low energy sweeteners can help with weight management."
Ten of the papers focused on diet beverage consumption in prospective studies of adults and children with follow-up periods ranging from one to 20 years. Six of these studies linked use of sweeteners to a lower risk of obesity.
In an analysis pooling data from the three largest prospective studies, researchers found a 0.10-kilogram (one fifth of a pound) reduction in body weight for each daily serving of diet soda consumed over four years.
At the same time, a larger analysis of nine of these studies found no connection between sweeteners and increased weight.
The research team also looked at 56 previously published articles reporting on experiments that assigned people to eat and drink different types of products for a day or less.
Taken together, these results showed consumption of sweeteners instead of sugar was consistently linked to the consumption of fewer calories during the brief experiments.
People in these studies consumed roughly the same number of calories regardless of whether they drank diet drinks with sweeteners, unsweetened drinks, or water, the analysis found.
When researchers examined interventions lasting longer than a day, they also found sweeteners linked to lower calorie intake than either sugar or water.
One limitation of this fresh examination of previously published studies is that the types of experiments and participants varied widely and didn't focus exclusively on people using sugar substitutes to shed excess pounds or maintain their current weight.
"While a response to consuming a low-calorie product might be to relax restraint in relation to other aspects of the diet, another response might be to redouble one's efforts to reduce calorie intake," Rogers noted.
Dieters should also keep in mind that even if sweeteners don't wreak havoc on their resolve, diet drinks are still not the ideal beverage, said Dr. George Bray of the Pennington Biomedical Research Center in Baton Rouge, Louisiana.
"Basically, water from safe sources is the best option," Bray, who wasn't involved in the study, said by email. "Adding a bit of lemon, or a packet of an artificial sweetener if you must, is another way to go."
Several of the authors on the study have ties to the sugar and sweetener industries. Rogers, for example, has received grants from Sugar Nutrition in the U.K. Research team members also got funding from organizations including the Dutch Sugar Bureau and companies that sell sugar and sweeteners.