No will-power. No ability to say "not right now". Not enough gumption to push your plate away from you when you know you should. Not enough energy to make yourself go sit outside on a beautiful evening (far away from the kitchen). When the day has used up your reserves and even though you know you've stomach is telling you you're at a 9 -- your mouth is telling you you're not done with your "eating entertainment" -- what happens then???
You know what? Even though you've got nothing left to give -- what happens then is still up to you.
So what ARE you going to do then? Your call.