A so-called top nutritionist, Dr. Gavin Frost, declared Tuesday night at a nutrition conference in Australia that Teletubbies are turning the world's children into tubs of lard by being poor -- or, rather, "fat and jolly" -- role models, say news reports from Down Under. This latest slam to hit the British children's TV show that airs in America on PBS came Tuesday night at a nutrition conference in Australia, where Frost's frosty comment was picked up by news agencies. "The question is whether these unfortunately named characters are helping to entrench poor messages that being fat and jolly are attributes to aspire to," Frost said, referring to the cuddly Po, Laa-Laa, Dipsy and proud little Tinky Wink. A rep for Itsy Bitsy Entertainment, which produces Teletubbies, told the New York Post that Frost's allegations are "absurd . . . If you're going to start picking on fat things, then what's going to happen to Humpty Dumpty and Santa Claus?"