no it wont...your body needs a certian amount of calories to survive..so if u only eat 1 meal your body will go into starvation mode and store anything u eat as fat for fuel....unless u want to end up like one of those skinny-fat poeple(anorexic's) i suggest not doing it. eat MORE portions like 6 meals a day to speed up ur metabolism, but eat healthy so u dont eat much fat, carbs, and stuff.