When I think about idol, that is someone, who is perfect and whom I look up to. Idol means someone, who has all the qualities, which I too would like to have it in myself. Idol is the perfect example, whom I like to follow and eventually want to be like him or her. But, my idol can be totally different from your idol. Your idol may not be the one whom I look up to. Idol cannot be the one size fit for all. In fact idol is the one who have qualities, which I do not have, and still we like those qualities.
But, sometimes the concept can be superficial. What if we idolize the person, who actually suits us the best? Unknowingly, we try to justify ourselves and justify our situations through other's life. And idol becomes the one who is more or less like us. This may stop one to go beyond own limits. Though, I strongly believe everybody has the capacity of going beyond his or her limits.
For example, thin people appreciate size zero concept or look up to celebrity who are in that category. On other hand, heavy ones may idolize the person or celebrity who flaunts his or her body by saying this is real. Certainly, it is not a good idea to compare anybody without knowing their health condition and why they are in particular category. But, I would say this is human tendency to look for easy things and justifying it. Being Thin is not Fit and Being Fat doesn't make you Real, it just makes you Fat. Next time when you look for the idol, just think is he or she really having the qualities, which you are looking for or he or she just suits you best.