How your body partitions nutrients is important. It's the difference between storing most of what you eat as body fat or "sending" those nutrients to muscle to support growth and performance. So how does nutrient partitioning control leanness? Let's make an analogy.
Mike and Fred both work at a remote outpost. A plane drops a food package every day for the both of them to divide as they will. It has suitable protein, carbs, and fat for two people.
Fred's a fat and lazy guy. Mike is muscular, does all the work around the place, and trains with weights. What happens if Mike insists, "I do all the work around here, so I'll take what I want and you pick up the scraps?" Mike's nutrient intake will then support his weight training and work. He may gain muscle mass. As for Fred, he may lose fat.
But what if instead Fred grabs as much food as he wants, beating Mike to the plate? Mike's likely to lose muscle mass and body weight, while Fred gets even fatter. In either case, the fellow receiving only leftovers would be getting enough nutrition to survive. Even if it went on for years he wouldn't die; he'd simply stabilize at a lower body weight.
Mike and Fred's body fat set points would be determined by who grabbed food first and how much that person tended to leave for the other. In this analogy, Mike is your muscle and Fred is your fat. And "who grabs the food first" is your nutrient partitioning.
To control your body's nutrient partitioning, send more food to muscle, and lower your body fat set point, look into Indigo-3G® (C3G). Need more detailed info or want to know more things you can do to manipulate nutrient partitioning? Check out the related links below.