I always find it funny when people assume that a person is just born a certain way. Sometimes we just assume a person is naturally lean because they are lean most of the time, or they are naturally strong because they lift a lot of weight in the gym, or they can eat a lot of food because they have a fast metabolism.
People make these judgements or assumptions because they only see part of the picture which is the final result, they don't see how that picture became what it is, what was involved in the making of that final result.
I stay under 10% body fat all year round but that does not make me naturally lean. It takes commitment to my diet and making sure I burn plenty of calories each day with exercise. I can get fat just like anyone else.
People tell me my strength is only because I have a lot of muscle on me, did they stop to think where I got the muscle from. Was this muscle always there? Did it just magically appear overnight? Or maybe it has taken years of pushing myself at the gym way beyond where most people are comfortable to venture. Muscle is a byproduct of strength, strength is a byproduct of effort.