I was drinking 2-4 aspartame-sweetened drinks a day for a while and losing slowly. The past couple weeks I noticed my weight loss speeding up, and thought -- what the heck??!

Then I realized: my department was moved to a different floor where the soda machine only had Coke products (ewww, canned Diet Coke...)--so I started putting Diet Rite in the fridge and drinking that instead with lunch. My aspartame consumption dropped to 0-1 drinks a day. It may be a coincidence, but I have to wonder if maybe the daily Diet Pepsis were slowing me down. Dunno.