How about just feeling plain crappy? If you've ever had a bad flu, you've probably lost some weight because you just didn't feel like eating. Then, again, there are some terrifically overweight people that eat constantly because they felt crappy and eating makes them feel better; so, they eat all of the time to avoid feeling crappy again.
Take me for instance. Right now, I feel, well, crappy. So, to help me feel better, I am going to open a pack of cinnamon poptarts, stick them in the toaster and smother them with butter when they pop up. I will also feed another addiction of mine at the same time, coffee! Nothing goes with butter-smothered poptarts like coffee.
I can feel a pick-me-up on the way!