I work as a lunch time supervisor in infant school and I can say with out any quarms that there is a large proportion that start school that have never or very rarely sat down to a family meal. And if they have, they have been allowed to just wonder off.
Not that it has much to do with the basic provision of nutritious food but they don't know how to hold a knife and fork, sit to the table or actually eat a meal. We have a real struggle teaching these kids how to sit and eat. And I won't go into their inability to distinguish a sweet from a piece of fruit (but I could lol).
Even the so called afluent families think chocolate sandwiches, chocolate biscuit, cake, and crisps with perhaps a packet of fruit flavoured sweets is a healthy lunch because they PANDER to their children.
It is an endevour, by the present government at least, to ensure that every infant school child (with hopefully a roll out to juniors later) has access to at least one 'healthy' meal a day.
That one meal a day is hardly likely to educate the child properly but it is a start!!