Being lean consistently for life, not just after a 3 month diet is a LOT like becoming a millionaire. It's NOT just something we can make happen in the short term, nor can we hope to maintain it if we "strike it rich" with a get quick scheme if we don't learn the discipline, the habits, along the way we need to maintain it. 

Leanness, much like millionaire status, emerges as a "side-effect" of our lifestyle choices, our mindset, and our daily actions.