I do belive that all people in health fields do have a unwritten obligation to be a role model of health and fitness. Some people can by hypocritical though. Just becuase they are unhealthy does not mean they lack the knowledge to make another person healthier. Actions do not coorelate with knowledge. Just becuase you know the correct thing to do, does not mean you will do it, and vice versa. Some smokers say do not smoke as it will ruin you, they are right even if they do smoke themselfs. I have had gym/health teachers who are overwieght yet they still gave out challenging workouts, and had a great knowledge on health based topics. Another thing some people who appear healthy are not really healthy. You can look toned, skinny, and look healthy, while smoking,drinking to excess eating a lot of sweets, and doing other unhealthy things as long as you burn more calories than you use, and/or are good at using make up. Muscular fit looking males may be taking steroids. A question is would you rather follow the advice of a obese registered dieatition who you know smokes on their free time, yet has extensive knowledge of what to eat and what not to. Or a skinny muscluar random person who does not have the same knowledge yet is fit becuase they are more obsessed with exercise, and take care of themselfs??