I have the opposite problem from most of you, I am trying to put weight on. I am working out regularly, 5 times a week, usually for 45 mins to an hour. I work lower body (legs, stomach, lower-back) 3 times and upper body 2 times. Lower body work out consists of 15 mins of bike, machine squats, real squats, leg extensions, leg curls laying down (cant remember name), sit ups, hypertensions. For upper body I try to hit each muscle group (pecs, arms, shoulders, back) with 4 sets each, low reps. I don't take any shakes or anything like that, just a some multi-Vitamins, eat pretty healthy (if basic). The problem is a I am stuck at 145 lbs. and can't seem to get beyond that. Any suggestions appreciated.