There was no eat at school lunches (50s and 60s) and only kids bussed in from rural areas brought bag lunches made by their moms.

Kids like me who did not live in a rural areas WALKED home for lunch (in my case, 1/2 mile home then back to school, another 1/2 mile). Seems to me a pretty healthy lifestyle and this was in Canada so in winter, our knees (girls wore skirts, trousers were only for boys!) were usually blue or purple with cold every day all winter long as we trudged to school and back and then to school and back. We walked two miles a day!