Gaining

Eat what you would normally eat just more of it. Maybe try getting a calorie counter so you can keep track of how much you are eating. Overall you want calories gained to be greater than calories expended.

Generally restaurants/fast foods are slightly more expensive. If you want to do this cheaply, heavy cream is a good way to add calories and I wouldn’t recommend doing this long term but little debbies snacks and the like are super cheap and have a lot of calories.

No problem. Good luck to you.

Cheep beer!

I've been gaining a lot of weight by drinking heavy whipping cream. I buy about 12 quarts per week, and I'm only paying a little over $37 for that.

Out of all the things I've tried to gain weight, heavy whipping cream has definitely been the cheapest and most effective.