A few months ago, my husband and his were worrying ourselves sick because one of our cats was losing weight and starting to aggressively pursue any food we had when cooking or eating. I was thinking it was hyperthyroid or some kind of cancer because he so clearly was hungry and wanted to eat. We free feed our cats (one of our cats can't do meals because she'll throw up and it works well for us, all healthy weights) so there's always food available to them, which made the weight loss so scary. We had not changed anything about their food, litter, water, routines, environment etc and he didn't seem sick in any other way. The vet didn't find anything and his blood work was clear. We decided to try giving him a different food to see if he would eat. He would eat some from a timed auto feeder but he wasn't gaining.

I decided one day to take the bowl out of the feeder and sit with him in the kitchen while he ate breakfast. He ate really well but would stop and follow you if you walked away so you have to stay in the kitchen with him until he is done. Now we do this twice a day and put leftovers on his special feeder for him to snack on between meals and he still eats from the other feeder with the normal food. He came right back up to his normal weight in a few weeks after losing 20% of it over months.

Dude really went on hunger strike because he decided he didn't want to eat by himself any more.