Well, after some break time I decided to finish my Food Effects List. This is meant to be a supplement to my item effect list. Refer to it to find out what the numbers mean. I have broken down the list to include what each of the foods do when liked, disliked or neutral. So here we go, here's what the Foods do:
Potato: Liked: +1 Spoil, -1 Fear, -1 Form Neutral: +4 Stress, -4 Spoil, +3 Fear, -1 Form Disliked: +16 Stress, -10 Spoil, +4 Fear, -1 Form
Milk: Liked: -3 Stress, +3 Spoil, +1 Form Neutral: -2 Stress, +1 Spoil, -1 Fear, +1 Form Disliked: +4 Stress, -4 Spoil, -4 Fear, +1 Form
Fish: Liked: -6 Stress, +3 Spoil, +2 Form Neutral: -3 Stress, +2 Spoil, +2 Form Disliked: +2 Stress, -2 Spoil, +1 Fear, +2 Form
Cup Jelly: Liked: -7 Stress, +1 Spoil, -3 Form Neutral: -5 Stress, +1 Spoil, +1 Fear, -3 Form Disliked: +1 Stress, -1 Spoil, +1 Fear, -3 Form
Meat: Liked: -8 Stress, +5 Spoil, +5 Form Neutral: -6 Stress, +4 Spoil, +6 Form Disliked: +1 Spoil, +1 Fear +6 Form
Tablets: Liked: -15 Stress, +3 Spoil, +2 Fear, +3 Form Neutral: -13 Stress, +1 Spoil, +2 Fear, +3 Form Disliked: -10 Stress, -1 Spoil, +2 Fear, +2 Form
Hopefully this can help you make decisions on what to feed your monsters. As you can see, what you feed it can make a big difference in your monster's welfare.