So, I am somewhere at 120lbs and somewhere at 5,8-6ft. I got motivated to try to gain mass a month ago, but had to stop because the mass calorie consumption started to bring back stomach issues, which I used to have a problem with but managed to get rid of them. Anyway, I have been wondering If I should start lifting weights, going to the gym. And if i can gain mass without overeating all of the time. I also wonder if I would even be able to stick with it since I am not genuinely interested in the lifestyle, I would be doing it just out of insecurity.