why?

Why is it that I complain about seeing weight gain and changes in my face - yet I cannot stop eating?!! I don't eat a ton at each sitting but I eat pretty much all day long. There is less and less room for me to put food since the babies are getting so big - but man I eat a lot! I am a little anxious to see how much I've gained at the doctor on Thursday but excited at the same time. I was told to try to gain roughly 24lbs by 24 weeks. I'm 24 weeks this week so we will see!!