Don't count on diet soda to get you through this season of weight gain, researcher warns

"A study published last year found that rats fed saccharin-sweetened yogurt gained 20% more weight than rats that ate yogurt made with glucose. It also found that the saccharin-eating rats experienced a smaller increase in body temperature after their meals, indicating that their bodies were less revved up to burn off extra calories."

http://latimesblogs.latimes.com/booster_shots/2009/12/artificial-sweeteners-weight-gain-obesity-ludwig.html