I’ve got a superfast metabolism and am very slim. My diet is the same as it was in GPP while doing hypertrophy weights upper+lower (minus quads) and I gained no significant mass… it is purely the advent of squats that lead to the mass, and i’m pretty sure it’s water-weight… they fill like balloons! I feel calorie counting isn’t necessary… the body uses what it needs, so excess calories won’t increase muscle mass unless there is a hypertrophy stimulus, otherwise you will gain fat… which isn’t the case for me.