I should gain about 5 lbs.
If I eat until full at every meal, I maintain the same weight. I don't want to do protein shakes or powders or pills. If I want to gain some weight, do I have to stuff myself and eat until bloated? It seems like that's what I have to do to gain weight. Any experience here? Is it unhealthy to stuff myself 4 times a day if it helps me gain? I'm a little underweight, not just trying to be muscley.

Also is a heavy reliance on cheese and unsweetened chocolate ok to gain, or am I better off health wise overeating meat and vegetables and potatoes?

I'm not in a strong state right now, I try to crank out a couple pushups in the morning sometimes, and I walk about 2 miles a day, that's all for exercise.