Artificial sweeteners make it harder for people to control how much they eat and their weight, according to a new study.

In fact, researchers from Purdue University said those who want to lose weight may want to pour the diet soda down the drain.

Their report in the journal Behavioral Neuroscience looked at rats that ate yogurt sweetened with glucose, which has the same calories as table sugar, and those that ate saccharin.

The sweetener-fed rats ate more calories, gained more weight and put on more body fat, researchers Susan Swithers and Terry Davidson wrote.

They suggested that the sweeteners make it hard for the body to keep track of how much has been eaten, leading to extra eating.

They also found that while the metabolism usually revs up before eating -- including a higher body temperature -- rats fed the saccharin did not have that response. That could make it harder to burn off calories.