My 4y/o brings a box to school with 1 piece of fruit (some bring a cookie/oat bar or something but the school encourages fruit) and a bottle of water which is eaten around 10:15 I believe. I think this is only for young children.
By the way, if a kid forgets his or her fruit they make it point to share, I like that policy. Also I hear from colleagues more and more schools are switching to water only to battle weight increase in children, although this leads to some discussion :)
Edit: see below, the Netherlands is waking up I guess :)