What caught the attention of Michele Belot and Jonathan James, though, was the way Oliver’s project had been implemented. Belot and James – economists at Nuffield College, Oxford, and at the University of Essex respectively – noted that the campaign had created a near-perfect experiment. The chef had convinced Greenwich’s council and schools to change menus to fit his scheme; he mobilised resources, provided equipment and trained dinner ladies. Other London boroughs with similar demographics received none of these advantages – and indeed, because the programme wasn’t broadcast until after the project was well under way, probably knew little about it. The result was a credible pilot project. It wasn’t quite up to the gold standard of a randomised trial, but it wasn’t far off.
Thanks to the UK’s exhaustive school testing regime, Belot and James were able to track pupils’ performance in some detail. They concentrated on primary schools, figuring that secondary school pupils could (and probably would) avoid eating school lunches that were too worthy.
Their answer – a provisional one, since they are still refining the research – is that feeding primary school kids less fat, sugar and salt, and more fruit and vegetables, has a surprisingly large effect. Authorised absences, the best available proxy for illness, fell by 15 per cent in Greenwich, relative to schools in similar London boroughs. And relative to other boroughs, the proportion of children reaching Level Four in English rose by four and a half percentage points (more than six per cent), while the proportion of children achieving Level Five in Science rose by six points, or almost 20 per cent.
People have a tough time believing that seemingly-small changes can have substantive effects; for whatever reason, we assume that the vast and the ambitious are always preferable to the small but sensible. (See also: geoengineering.) There is no reason whatsoever that the above finding should be surprising. We’ve known for years that people who eat better are healthier. We’ve even known that people who eat better often have better cognitive skills. But we ourselves don’t feel instantly smarter when we eat broccoli instead of buffalo wings (rather the opposite, actually), so we assume that the effect must be purely theoretical. I think that one some level we are deeply uncomfortable with small-scale solutions – that painting our roofs white can substantially mitigate carbon buildup, say, or that we can basically eliminate hospital infections by making sure doctors wash their hands – because they throw into question almost everything we do. How much harm have we been causing, without even knowing it?
To get back to school lunches, though, many parents are terrifyingly cavalier about what their children eat at school. Even parents who check nutrition facts and stick to the veggie aisle in the grocery store have no idea, literally no idea, what their kids are putting into themselves every single day. The rotating menu at my junior high school included a fair number of items – a strange sort of square, Chicago-style pizza, sloppy joe’s, some kind of poultry burger – but almost none of it would I eat today. And – like almost every nutrition and public-policy problem – unhealthy school lunches disproportionately sicken the poor.