What is a good diet if I want to gain weight?

Carbs, lots of carbs. Get protein shakes that have carbs in and train hard and with heavy weights and low reps.

i don’t think it is agood idea to gain weight or to lose way in a fast way. No matter if you want to gain or lose weight, the best way of doing it is do it in a healthy way. Still you need to eat more fruit, vegetables, enough calories etc. Then, you can add more milk in your breakfast and dinner. Still you need you exercise regularly. Good luck :)

How fast we talking? Any excess of calories causes weight gain. Period.

The quickest way would be to go 500+ over maintenance calorie intake which gives you around lb. a week. Anything over 500 calories above would increase that number.

Example: Main. - 2800/day 1lb. - 3300/day - 3500 calories above in a week 2lb. - 3800/day - 7000 calories above in a week 4lb. - 4800/day - 14,000 calories above in a week

Note however anything above a pound a week is usually going to be fat, unless your activity level is that of a Strongman or someone who burns ridiculous calories a day.

Complex carbs are calorie dense so things like brown rice, whole grain pasta, oatmeal, anything whole grain are good, but these are also satisfying so they ‘kill’ hunger by digesting slower.

You can really just eat whatever as long as you get 1g of protein/lb. and .3g-1g fat/lb. along with calories over maintenance.

High protein, high carb, and healthy fats.