Well, we shall see whether the government's new policy of free school meals for all under 7s will deliver its desired outcomes in terms of increased pupil concentration in the afternoon, and greater attainment – well, in the narrow sense that government sees attainment. The general evidence for both of these is pretty plausible, though context is likely to be a confounding factor.
The government's new policy is based on two pilot studies, and the BBC Radio 4's More or Less asked the researchers involved in these to comment on how soundly-based the policy seems. You can listen to them here. Needless to say, it's not at all clear-cut. One snippet from the research was that the amount of fruit eaten at lunchtime in the experimental groups went down. One question is, did it go up at home to compensate? Another is what does this say about school meals?
It will be instructive to see whether the policy, which is both a middle-class subsidy and an electoral bribe, will succeed in getting anywhere near 100% take up. I suspect it will not come close. There are (at least) two groups who will resist:
[i] those parents who think that the standard of food in the school meals offered to their child is too poor and that their own packed lunch is better nutritionally. Generally, these are parents who know and care about food and nutrition. They may (or not) be organic in preference, and they are not all in north London. A recent Woman's Hour feature on BBC Radio 4 saw this bunch well represented – and vocal.
[ii] those parents who think that the food in the school meals offered to their child is not to its liking and so opt for the packed lunch quiet life. By and large, these are not parents who know and care about food, though some obviously do. They are largely invisible to Radio 4.
We shall see. We'll also see how many school meal fascistas try to ban the packed lunch – probably on equal opportunities grounds.