The fourth sentence of paragraph 68 begins:"However, the Committee also recognises that if the school day were lengthened to accommodate a longer lunch hour or a staggered lunch hour".I would rather it said "altered" instead of "lengthened".The paragraph continues:"then there could be costs in terms of teaching time and administrative costs".Although that is using the word "costs" in a way that is not exactly accurate, that is fair enough, and there would indeed be effects "in terms of teaching time and administrative costs".I would use the word "effects" instead of "costs".