Who 'bombards' the children with ads, exactly? I'm curious. Where are kids seeing the ads in a completely involuntary manner?

Personally, I have read that kids need dietary fat and I believe it, especially when they are young. It's needed for brain development. Sugar and starches are the real battle. Kids tend to be active, plus they have all that growth hormone (so it's not as harmful as later in life when that slows down), but still.