I have periods of a few days every so often where I completely lose my appetite due to my ADHD medication. It's fascinating how something that's usually such a pleasure becomes a complete chore. I need to force myself to eat, literally stuffing food into my mouth and methodically chewing, there's no enjoyment whatsoever, no matter what I eat it feels like I'm eating sawdust.

Usually when it happens I switch from eating solid food to liquid meal replacements and tinned fruit, things I can more or less just pour down my throat.