Actually... (oh dear, this isn't going to be a popular answer!), the jury's still out on this one. It's a saying that has been around for so long and penetrated our culture to the extent that everyone assumes it's true without remembering specific details or sources. You will find many seemingly reputable sources swearing that it's true, but interestingly enough they report widely different figures for the number of muscles. Some of the more popular ones are 43 muscles in a frown vs. 17 muscles in a smile and 62 muscles in a frown vs. 26 muscles in a smile (nice symmetry... too nice if you ask me!). So we definitely know what majority opinion is on the subject, but they don't seem to have anything to back it up! Things are further complicated by the fact that those crazy researchers who are actually puzzling over this can't agree on certain fundamental things: do they count muscles with a major involvement, do they count every teeny-tiny muscle that twitches even if it doesn't play a large role, do they count eye muscles because some people's eyes crinkle up a bit when they smile, etc., etc.? Frowning could involve more muscles, but smiling could still require more effort if those fewer muscles need to be flexed more. Do a random google search like I did; I swear you will find all of this and I am not making it up! Nobody knows for sure, but everybody has ideas. A few facts that may or may not also be relevant to answering the question: studies show that people are more apt to smile when they see other people smiling and frown when they see other people frowning, some believe that smiling just seems easier because we do it more and the muscles are thus better conditioned for it, and the sort of smile that we label "insincere" requires significantly less muscular effort than a sincere and spontaneous grin. I vote for smiling, regardless of how many muscles are involved! :)

Put it this way, if you smile, and it uses more muscles, chances are you'll use more calories and so lose more weight (about the same amount in a hundreth of a raisin).

will it takes more muscle beacuese all you do is relex no stress and there u go a frown thats clearly the only reson and if u cant simle then your weak