Lifestyle tips

Safe gain?

Am considering to push my gain a little, but really dont want to risk health or the digestive system.

How many calories would be doable a day and are there any other precations that might be necessary?

I am loosely thinking of adding around 1000-2500 calories to my normal eating habits which are rather regular in terms of 3-4 meals a day etc. I dont need to be able to keep this for super long but a couple of months would still be good.
1 year