Yup - did it here, went from mountain dew, to double mountain dew then double mountain dew diet with half that calories :P (actually switched to diet mountain dew or coke zero). I lost about 10lbs then gained it back which didn't make sense to me because I was pulling at least 600 calories out of my daily diet. It wasn't until I switched to plain black coffee that I went on a steady decline in weight. (I had to do more than that long term but that's hard proof to me that the artificial sweeteners are still futzing around with the metabolism in some way)
The one I know best is "I've never seen a skinny person drinking a diet coke."
I have.
Once you ever begin counting calories, the first thing to go is caloric drinks, and the habit never goes away.
Yup - did it here, went from mountain dew, to double mountain dew then double mountain dew diet with half that calories :P (actually switched to diet mountain dew or coke zero). I lost about 10lbs then gained it back which didn't make sense to me because I was pulling at least 600 calories out of my daily diet. It wasn't until I switched to plain black coffee that I went on a steady decline in weight. (I had to do more than that long term but that's hard proof to me that the artificial sweeteners are still futzing around with the metabolism in some way)
It's also possible that your caloric estimates were way off.