So, I am well aware of the thermogenic properties of caffeine, how it keeps your metabolism going, and how it works as a mild appetite suppressant. Lately (the past month) I have noticed that I am having trouble maintaining my lean-ness... at least a lot more than ever before. My workouts are still the same, and if anything, my cardio is at least on par with, if not better than before. I live in downtown Chicago and walk and bike EVERYWHERE I go. I have noticed that on top of not being able to stay as lean as easily, I am ALWAYS hungry. I can't stop eating and I am basically starving myself to stay at my caloric deficit of 2,200 cals.... which used to be no problem. The only thing in my diet that has substantially changed is the amount of coffee I drink. During the school year I was averaging 3 or 4 cups a day of regular coffee (usually from starbucks) and now that it is summer time and I only have two classes I tend to only drink one cup and sometimes don't have any. So as a rough estimate (figure 200mg per cup of coffee X 3 or 4) I WAS consuming 600-800mg caffeine daily, versus now, which is 200-300mg and sometimes none at all. Is it possible that my reduction of 3 cups a day of coffee is the reason that I am having such trouble holding my deficit and keeping lean on the same diet? I suppose it seems plausible, but I wasn't aware caffeine could effect it that much.