Again, this one goes without saying. You can’t expect to achieve a leaner body by continuing your unhealthy eating habits. Not that you should drop everything in your diet immediately and exchange it for “healthy” food. You would end up miserable and revert to your old habits within a month. Instead, practice moderation and don’t overindulge. Also, phase certain unhealthy foods out of your diet while introducing healthier foods. The transition will be easier to make and a lot easier to maintain.