Is it ok for grandparents to spoil kids with lots of candy at the holidays?

Not exactly.: Grandparents are special and are priviledged. So they don't need to follow the same rules as the parents, but candy is not the best way to spoil your kids. Maybe you can talk to them and come up with some other spoiler.

Multiple layers: This is a more complex question than it might seem on the surface. As dr. Bergman indicated, grandparents often are exempted from some rules that parents impose, but it is also important that they not undermine parental authority. Loading kids down with candy has problems ranging from weight to tooth decay. The broader question is how can grandparents be a positive force in the child's life.