Think of it this wayIf there was group health insurance for 10 individuals where 9 individuals were obese andor frail and elderly , one would predict their health care costs to be large . The premiums , then , would have to reflect this higher cost . So the one healthy individual in that group of 10 would have to pay a higher premium . Conversely , if you have group health insurance for 10 people where nine out of 10 are fit and young individuals , one would expect the health care costs to be quite low as fit and young individuals rarely access health care services in general . The premium for this group could be expected to be lower than the previous group mentioned . Young and fit cheaper carObesefrail elderly expensive car