I had a skin fold test done prior to starting training, I was 22% BF (IIRC) at 6' and 190lbs.
At the end of the 1 1/2 month training, I weighed in 198lbs, ~20% BF.
The trainer did the math and I had gained 12 pounds of muscle and lost 4lbs of fat.
Diet was regular cafeteria food, whey protein...