My GU Garbage

My most wasteful habit is throwing food away. I don't finish most meals, usually leaving about half of it on my plate, so I empty that into the garbage can rather than putting it in a container for later. Later just never comes, and 2 weeks after my husband empties the fridge of all "hairy food". And most of it is mine.
I forget to eat during the day, usually the result of my medication affecting my appetite and my lack of self awareness showing up as an intense headache late in the afternoon because I didn't realize I hadn't eaten anything yet, especially when I am hyper focused on something interesting.
It is very wasteful to throw food away and somewhat guilt inducing to realize that the tons of food in the garbage could have been appreciated by someone in need. Bummer:(
I've tried to get a handle but really, I'm at a loss. Sometimes, I can mix the food from my plate with the dog food as a treat for Boo, but often it's not appropriate food for him so I still end up throwing it away.