This mainly depends on the individual. Not every girl doesn't like fat boys, but how fat you are. If it is obvious that everyone calls you fat and doesn't call you by your name, you may lose out in blind date, because girls ignore your other advantages and only see your figure. If you care, you can go to the gym to look well-proportioned and not out of shape. If the height is passable, it is ok to look a little fatter. If you are average in height and obviously overweight, you may be brushed off immediately when dating.