Donno whether 'thin is in' but certainly being fat is not an healthy sign. Its an open invitation to all sorts of health problems. If not at an early age, certainly when u grow old u r bound to face serious health trouble. So before its too late, always better to draw a line. For that u dont need to crash diet. U just need to maintain a proper exercise routine alongwith healthy diet. Should b consistent in whtever u undertake and thats the path to success.