What does a diet consisting largely of ultra-processed food do to the body? It’s a question Dr Chris van Tulleken sets out to explore in a documentary on this cheap and convenient food type.
In What Are We Feeding Our Kids?, which airs on BBC One on May 27 at 9pm, Dr van Tulleken undergoes a gruelling experiment of eating a diet consisting of 80% ultra-processed food for four weeks, with very unpleasant results.
Ultra-processed foods are defined on what’s called the NOVA scale, says registered nutritionist Charlotte Sterling-Reed, of SR Nutrition. These aren’t simply ‘modified foods’ – like frozen or tinned products – but foods that have undergone multiple processes which result “in little, if any, intact whole foods being present”. Some examples include: soft drinks, sweets, packaged snacks (like biscuits, pretzels, crisps and popcorn), and ready meals.
These ultra-processed foods often contain additives and ingredients – and in many countries, they account for the majority of calories we consume.
What does eating ultra-processed food do to the body?
After a month passed, Dr van Tulleken was experiencing sleep problems, heartburn, low mood, sluggishness, piles (caused by constipation) and low libido. “I felt ten years older,” he said. He gained almost 7kg and brain scans showed the food had almost become addictive to him – which made him question how this would impact young children.
Studies have previously found eating more ultra-processed foods is bad for our health. Three studies in particular linked eating a diet high in ultra-processed food to an increased risk of dying earlier.
The first, published in February 2019, revealed upping these foods by 10% in your diet is associated with a 14% higher risk of early death. Meanwhile, two European studies published by the BMJ revealed a link between eating ultra-processed foods and a higher risk of cardiovascular disease and early death.
Dr van Tulleken’s concern is that this kind of diet is contributing to rocketing childhood obesity rates – and that the health effects on kids could be even greater.
So what can we take away from this? As always, it’s a matter of eating things in moderation. “Most of us know we should be eating a balanced diet and trying to do things such as cook from scratch, eat more fruits and vegetables whenever possible, as well as reducing intakes of processed (specifically ultra-processed) foods,” said nutritionist Charlotte Stirling-Reed.
Ultimately, these studies – and Dr van Tulleken’s experiment – confirm what’s recommended for people wanting to live a healthy lifestyle: we need to have a balanced diet and choose minimally processed foods as much as possible.
Stirling-Reed adds that we also need to remember all processed foods aren’t necessarily ‘bad’ for health, so you shouldn’t treat them all like the devil. “It’s about balance and context when it comes to what we eat and how it affects our health.”