http://www.telegraph.co.uk/topics/christmas/6824253/Santa-promotes-obesity-and-drink-driving-claims-health-expert.htmlNot that Santa Claus hasn't changed appearance in the past and all. He has, quite a bit. But such a negative reason to change him!
If the same person had argued that a tall, fit Santa would better embody the majesty and dignity of Christmas and the spirit that impels us to give gifts, then he might have a point worth considering. But this! You may as well object to Thanksgiving because you dislike turkey.