Does cooking corpses make them more nutritious to eat?

Solution 1:

It's actually not a straight yes, but only because if you're bad enough, cooking will have the opposite effect.

Cooking anything (not just corpses, but fruit and vegetables and all those other things) will alter the stat training that the food gives. If you're bad, you end up with things like grotesque meat or kitchen refuse - these give worse training (but still positive) compared to the base amount. If you're good, you end up making things like sushi and steak which give phenomenal multipliers to the stat training that the base food type would've given.

Of note, only resulting in better food will actually train your Cooking skill. If you're bad, you'll stay bad. And you should feel bad.

As such the answer to whether you should cook before you eat depends a lot on how good of a cook you are. Though keep in mind, cooked food also rots slower and usually weighs less than corpses do (all cooked food weighs 0.5s, almost every corpse weighs at least 0.7s nevermind the ones that weigh double digits), so if you wreck a room of bears then you aren't going to eat them all on the spot, so cooking will help have leftovers to eat when you get hungry. Or if your allies get hungry (allies get the same stat training you do from food, being the only reason they eat at all since they can't actually starve).