Diet soda is what you drink when you're trying to lose weight and still want a sweet bubbly glass of soda. It's also helpful for diabetics who can't eat too much sugar, but still, want to have a Coke now and then. New research shows that it might be causing people to gain weight rather than lose it and that can be dangerous for diabetics and frustrating for dieters. A study presented at the 2018 Experimental Biology Conference looked at how fake sugar sweeteners like Equal and NutraSweet are digested by the body. The study used lab rats and found that the animals did not process fat the same way after ingesting the sweeteners and there was muscle breakdown as well.