Godfray is a population biologist and the director of Oxford Martin School. He has published work in ecology, evolution and epidemiology, and has a particular interest in the need to adapt our food system to cope with the challenges of the modern world.
At the Guildhall on Monday, he spoke about the growth in obesity, the medicalisation of non-health threatening overweightness through anti-obesity drugs, and the surprising success of the sugar levy.
The struggle with obesity
According to Godfray, one of the biggest challenges facing the world today is obesity. Around 38% of the world’s population (around 2.6bn) is overweight or obese, and the number is only growing.
The ‘good news’, said Godfray, is that the fraction of people who are overweight is flattening. However, with obesity, the amount “just seems to be going up.”
Godfray warned that “this level of overweight and obesity, [when] projected ahead, [is] completely unsustainable for the NHS.”
There are a variety of responses to take. “You get a sort of hierarchy of approaches,” said Godfray, “so you can educate people about what good diets are, provide information such as labelling.
“Or you can do behavioural interventions, these behavioural interventions might be to encourage people to do more exercise and they might be nudgy things, like putting a vegetarian option in front of the meat option.” Exercise, however, while ‘unremittingly good’ in a lot of ways, is ‘not very effective’ in helping people lose weight.
Nevertheless, “all these things are good. But if we are serious about reducing some of the challenges in the food system on the health side going forward, we’re going to have to think about other measures.”
One of the reasons why education and behavioural incentives are so popular among politicians, suggested Godfray, is that “it puts the agency on the individual to do things.” Government intervention has, he pointed out, also shown significant success in helping people be healthier.
Godfray mentioned taxes and levies, using the example of the UK Soft Drinks Industry Levy, also known as the ‘sugar tax,’ which came into force in 2018.
At the time, he had thought that it was the wrong choice for the government to make. But he was pleased to see the eventual success of the levy. “This is one of the occasions where it is really nice to be wrong. We thought it wouldn’t work because it wasn’t consumer facing. And we underestimated the agility, and actually the creativity, that the soft drink industry has.”
Brave new world
Godfray also spoke about anti-obesity drugs, “a whole new class of drugs that will enable people to lose weight.” These drugs, which help people to eat less by making them feel fuller for longer, are predicted to have a similar market value to all cancer drugs put together in the future.
While the drug was originally developed to treat diabetes, many argue that it could contribute towards to mitigating the obesity epidemic.
Godfray, though, was sceptical. “I worry about issues to do with equity,” he said. “These are expensive drugs.” Poorer people will still be obese, he pointed out, if they could not afford the drugs.
He worried about the ‘medicalisation’ of people who were not overweight enough for it to pose a danger to their health. “I really worry about the pressure that they put on people . . . and of course, all the evidence shows that you have to keep on taking these things forever. If you come off them you go back to putting on weight.”
Finally, he felt that appetite suppression took the joy out of eating. “Do you really want to have your appetite suppressed,” he asked, “if you’re not at a level of overweightness or obesity that is challenging your health? I enjoyed food, and probably all of you do. I worry about this from a personal standpoint.
“So I think this is really interesting. I think this is going to be one of the major trends we've seen over the next few years in the market. I think we need a far more sophisticated conversation about it.”