I’ve tried quitting caffeine in the past, but the problem I run into is that I’m actually not a coffee drinker, but a Diet Coke drinker. I don’t enjoy the taste of plain water. So at a restaurant/drive thru/etc, my options are diet soda (with 0 calories) or something caffeine-free with hundreds of calories. When you’re trying to budget calories, that hurts a lot.
At least I’ve been able to reduce my overall consumption of caffeine a bit, but I haven’t been able to cut it out completely.