I've read that insulin is extremely anabolic (more so than testosterone). Insulin is great for packing on muscle but also increases fat gain. If you understand how insulin works, that kind of makes sense, but how does it fit into the context of calories in and calories out. Let say you eat 3500 calories per day and use up 2500. That leaves an excess of 1000. This will mean that each day you will gain 1000 calories of fat and muscle. The exact ratio depends on many factors. What happens when you take insulin ? Does the ratio change at all ? Does the balance of calories in/out change ? How does the claim of greater muscle gain + greater fat gain fit into this context ? Rainier.