Any local or regional board of education which serves breakfast or lunch to students shall offer students the meals described in subsections (b) and (c) of this section of these regulations. The composition of such meals, unless otherwise provided in these regulations, shall comply with the school breakfast provisions of the Child Nutrition Action of 1966 (42 U.S.C. 1773, 1779) and the National School Lunch Act (42 U.S.C. 1751, et. seq.) and any regulations promulgated thereunder, as from time to time amended. Foods available at schools during breakfast or lunch shall make a significant contribution to the development of healthy eating habits. Foods of minimal nutritional value, as defined under said federal laws governing school meal programs, shall not be sold during breakfast and lunch periods.