Citation: http://www.straitstimes.com/breaking-news/world/story/mcdonalds-fined-brazil-pushing-happy-meals-children-20130423
I think it's not only McDonald's that pushes unhealthy food to children.
I'm sure that McDonald's is the most famous fast-food company. But, it wouldn't be a reason to fine only that company.
By the way, it is ironic that McDonald's was fined for bad effects on children, despite the fact that McDonald's financially supports hospitalized children who can't go to McDonald's.