I have used about everything under the sun and trust me, you cannot beat Beverly International's Muscle Provider or Ultra Size for a powdered protein source when trying to seriously cut up or when dieting. I usually use ON's Pro Complex 55 during off times and when things start to get a little more serious I switch over to Beverly. Also, can add in there Liver and Amino tabs which are also excellent! The difference is night and day. Not an endorsement either, I have no ties with these guys at all.