Hi, im 18 in college and I go to the gym 5 days a week, trying to gain muscle mass. Been working out for over a year and went from 5 ft 8 125 lbs to 5 ft 8 160 lbs of solid muscle. I just ate about everything i could and was impressed with the results. However, since I have developed a strong muscular base, its harder to gain muscle mass now and I need to be more specific about what I eat. So how much calories per day would someone with CF who's 18 years old and works out 5 days a week need in order to gain lean body mass (500 calories above maintenance). What Im asking is what is my maintenance caloric intake requirements per day because I know they are different for people with CF. I dont really have any lung problems and haven't even had a single illness in over a year. Been to the hospital maybe once in the last 10 years.