Celebrity chef Jamie Oliver has stirred debate by calling the familiar five-a-day message “a lie”. Speaking to the Times, he argued that the real health benefits of fruit and vegetables only start to add up at seven, eight or even 11 portions a day. He’s not wrong that more is better. Research shows us that the more servings of fruit and veg we eat per day, the more benefits we see to our health. But the story of how five servings became the standard recommendation is one of science meeting pragmatism. When the five-a-day campaign was launched in the UK and Ireland more than 20 years ago, it was never meant to be the “perfect” target. Instead, it was a compromise – a number that struck a balance between the nutritional evidence and what public health experts thought people might realistically manage. Five portions were judged by researchers and marketers to be a simple, memorable and achievable slogan – one that wouldn’t scare people off.…