Good posture is something most of us forget about as we slouch on the sofa, but it's incredibly important not only to our looks, but also to our health - and can be the quickest, most effective diet in history! By simply standing straight and arching your back (a la miss Lopez), you'll not only help to diminish future back problems, you'll also instantly look more toned, more confident…and irrefutably slimmer! So, take notes from the celebrities who do it best ladies, and remember head's up!