City A.M.’s weekly feature takes the fiercest water-cooler debates and pits two candidates head to head before delivering The Judge’s ultimate verdict.
Ultra-processed food (UPF) has become a hot topic in the last couple of years, referring to mass-produced food such as cereal, fizzy drinks, ice cream and bread. If it has additives or preservatives in it, it’s a UPF. But is the panic a fad? Or is it killing us slowly?
The Debate: Are UPFs driving obesity?
Dr Alasdair Scott is a science director at Selph
Yes: UPFs undergo processing that makes them hyper-palatable and non-filling
The case for ultra-processed foods (UPFs) driving obesity is strong, as we have several strands of evidence that when put together present a compelling case.
Firstly we have evidence from observational, population-based studies that eating high amounts of UPFs is linked to a 50 per cent increase in the risk of obesity. We also see a “dose-response” relationship – the more UPFs someone eats, the higher their risk of obesity – which suggests that consumption of UPFs are not just associated with obesity, they are causing it.
To examine this causal relationship we’re lucky to have a well-conducted trial where researchers randomised 20 adults to either a UPF diet or a non-UPF diet for two weeks. Subjects were housed in a special facility and could eat as much or as little of the diet as they liked. Those on the UPF diet ate an extra 500 calories per day and gained a kilogram in weight over the two weeks compared to those on the non-UPF diet who actually lost a kilogram.
None of this is surprising when you consider that UPFs are actually designed by food manufacturers to make you eat more of them. UPFs undergo industrial processes and contain numerous additives specifically to make them extremely tasty (hyper-palatable) and non-filling.
UPFs don’t trigger that sense of fullness you get with whole foods, which is why we can eat a pack of biscuits in the blink of an eye. There is a clear motivation here: the more we eat, the more we buy and the greater the profits for food manufacturers.”
Chris Snowdon is head of lifestyle economics at the Institute of Economic Affairs
No: The label UPF is a farce
Asking whether ultra-processed foods (UPFs) drive obesity is like asking whether liquids drive liver disease. Insofar as alcohol is a liquid, the answer is yes, but alcohol is not the only liquid and there are other causes of liver disease. The category of UPF is so broad as to be nearly useless. It zooms out when we need to be zooming in.
UPF consumption is neither a necessary nor sufficient condition for obesity. If you eat a lot of crisps, chocolate bars and high-calorie ready meals – all of which are ‘ultra-processed’ – you may be at higher risk of obesity, but the same could be said of someone who eats too many chips, cakes and biscuits, none of which are ‘ultra-processed’ so long as you make them in your own kitchen.
Some UPFs are high in fat, sugar and salt, but some are not. Pound for pound, high calorie food is more fattening than low calorie food, but there is no known mechanism by which processing alone can make food more calorific. The nutritional content is all that matters.
It has been argued that food companies work hard to make their products irresistible, but the same can be said about every chef in the world and probably also your own mother. If the problem is that food is too tasty these days, campaigners should come out and say so. If they think that everybody should cook from scratch, they should say that too. There is no need to bring the fatuous concept of ‘ultra-processing’ into it.
The Verdict: The science is evident
Britain’s obesity crisis is no joke. One third of us are obese and nearly 40 per cent are overweight. This extra flab isn’t just a social taboo – it ladles illnesses onto people and causes needless deaths and suffering. UPFs have increasingly been highlighted by scientists as a reason for our fatness.
Crucial is the distinction Scott makes between association and cause: this “dose response” relationship he describes is very important; if the more someone eats of UPFs, the higher their risk of obesity, it is hard to argue that UPFs aren’t fuelling weight gain. It makes sense that companies have developed means by which to make us feel less full and consume more: we know this, just pick up a Pringle.
Snowdon’s line about food companies making irresistible products, just as one’s mother does, is neat – but if your mother was chemically altering her macaroni cheese to hoodwink you into eating more of it, don’t you think you’d have something to say to her?
The difference between UPFs and cakes, chips and biscuits – indistinguishable for Snowdon – lies in the fact that UPFs often masquerade as healthy or at least neutral (i.e. cereal, bread).