Gaining

Green gainer gets growing

If you want to get a lot of calories in with minimal food stick to calorie dense things like; fried foods, pastries, etc. *but don't forget to eat healthy stuff too lol*

As for when you'll start noticing, the general rule is a gain of 15-20lbs is what's noticeable. Though that'll also depend on your height and frame. But look for a visible *or tactile* change every 20-40lbs.
13 years