Most Helpful Guy
It's all about calories in/out. You want to gain weight, eat a lot of calories. If you want to do it cleanly, I don't think eating a tub of peanut butter is the best way to go.
Most Helpful Girl
not specifically. you gain weight when you sat more than you need. regardless of 'what'. PB is a concentrated source of fat, so you can get 200 calories form two tbs. but its also filling, so you might not end up eating a surplus.
if you are two tbs above what you normally eat eery day, youd gain around 3 pounds a months.