Soft drinks and weight loss don’t usually go hand-in-hand. But Pepsi aims to change that with a new drink the company has just launched in Japan, called Pepsi Special. The soft drink has an added ingredient, dextrin, that the distributor, Suntory, says reduces your body’s ability to absorb fat. So does that mean you can finally enjoy your soda with a slice of cheesy pizza, hold the guilt?

A 2006 Japanese study indicated that rats fed dextrin and fat at the same time absorbed less fat than rats that weren’t fed dextrin. The Japanese government certifies Pepsi Special and another dextrin-containing soda, Kirin Mets Cola, as “foods for specific health use.” But what works for rats may not work for people, and anyway, “There’s no study that shows that putting dextrin in a beverage is going to cause weight loss. After all, soda has a fair amount of calories,” says Joan Salge Blake, a nutrition expert for Boston University and spokesperson for the Academy of Nutrition and Dietetics.

Dextrin is a type of fiber. Soluble in water, and with a low viscosity, it should not negatively impact the mouthfeel of the beverage. Eating a diet rich in fiber can certainly have health benefits, says Blake.