I always thought Carbs were necessary for kids, to fuel their bodies because they have an active lifestyle (or at least they’re suppose to).
Carbs are necessary for anyone - it's where they come from that is the culprit. I try to stay away from any breads or ice cream (I said TRY) - and get them from vegetables and fruit. I still would rather eat junk, but I enjoy weighing less than I did last year too much to go back to my old ways. Plus I can do long runs know without the joint problems I used to have.
I still think Paltrow is an idiot though. It's one thing to keep kids from eating junk, but quite another to make them suffer because she is on the new eating plan du jour.