Diet Pepsi Changes Ingredients It now features a mix of 2 artificial sweeteners By Newser Editors and Wire Services Posted Dec 17, 2012 1:00 PM CST 44 comments Comments This undated photo provided by PepsiCo via PR Newswire shows the Diet Pepsi Logo. (AP Photo/PepsiCo via PR Newswire) (Newser) – Diet Pepsi has quietly changed its sweetener. Previously, Diet Pepsi used only aspartame, which is sensitive to heat and breaks down more easily. But beginning this month, cans hitting shelves feature what PepsiCo says is a "very small amount" of a second artificial sweetener: acesulfame potassium. The ingredient will "ensure consistency with every sip," notes the company; it can currently be found in a wide range of foods including baked goods, chewing gum, and gelatin desserts. The change, rumored this summer, comes as PepsiCo looks to reinvigorate its namesake brands (other parts of the plan: a new logo with a heart and the theme "Love Every Sip"). For now, Diet Pepsi remains the No. 7 carbonated soft drink with 4.9% of the market, according to Beverage Digest. Meanwhile, Diet Coke's share sits at 9.6%. Diet Coke, which still only uses aspartame, overtook regular Pepsi to become the No. 2 soda brand in 2010. Coke remains No. 1 and Pepsi is No. 3.