• Sarah Griffith

What are we feeding our kids?

Ultra-processed foods: what's wrong with them, how to spot them and how worried should you be if your child eats them?

In the BBC documentary ‘What are we feeding our kids?’, Dr Chris van Tulleken did an exposé on the effects of Ultra Processed Food (UPFs). He was inspired by the work of Bee Wilson, whose book First Bite, How We Learn To Eat, I would recommend to any parent interested in this subject.

He talked to researchers, visited Brazil to see the impact of UPFs there, and did a 4-week experiment on himself where he ate a diet consisting of 80% UPFs: a diet that is eaten by 1 in 5 people in the UK today.

Some of the more predictable results from his personal experiment included weight gain – 6.5kg in 4 weeks - heartburn, piles, constipation, insomnia and headaches.

Some of the more shocking results included increased appetite and a reduction in his capacity to feel full. This was caused by changes in the hormone signals sent from his gut to his brain: his satiety hormones decreased, and his hunger hormones increased.

Additionally, his UPF diet created new neural pathways similar to those seen in the brains of addicts, linking up the reward centres of his brain with the areas that drive repetitive, automatic behaviours. In other words, as a result of eating 80% UPFs, he was being driven to eat on autopilot, bypassing the usual feelings and signals that would have made him feel hungry or full.

Although this was just a one-man experiment, the results are significant enough to be published and to contribute to an application for further, more comprehensive research. This is terrific news, and I for one am grateful to Dr van Tulleken for putting himself through that experiment, shining a light on this issue and prompting more research.

It seems as though what many of us have felt and experienced personally, is now getting some scientific evidence behind it. And in my opinion this is long overdue. UPFs have been the cause of a lot of suffering for a lot of people for far too long. Author Bee Wilson poignantly described her feelings of self-loathing after her teenage binge-eating episodes involving Pringles, Crunchy Nut Cornflakes and white bread. Once she found out about UPFs she said, “I was asking myself the wrong questions. It shouldn’t have been ‘What is wrong with you?’ but ‘What is wrong with this food?’”

And for parents it helps explain why it can be so damn hard to create a healthy family food culture: vegetables versus chicken nuggets simply isn’t a fair fight.

The biggest worry for parents whose children eat UPFs, will be seeing the brain scans in the programme and wondering if this means that your children are wired to eat unhealthily for life.

Is it ever too late to change?

Of course, when it comes to feeding our children, prevention is going to be easier than cure and steering away from those foods in the first place is great if you can do it. But if you’ve gone down the route of serving lots of UPFs to your children – and there are many very understandable reasons why you might have done that – and you now want to make changes, is it too late?

I would argue, no, absolutely not. It’s likely to take patience, commitment and the willingness to learn a host of new approaches to feeding your children - but I’ve done it, and so have my clients. There are evidence-based techniques that absolutely do help children to accept a wider range of foods and to eat a more varied and balanced diet.

The best place to start is to identify the UPFs in your diet and swap out as many as you can

UPFs are so prevalent that it’s understandable if you don’t realise just how many of them you and your children are eating. So taking stock is a good place to start.

A useful rule of thumb is to glance at the ingredients. Is there anything you don’t recognise on there, or that you’ve never seen in a cupboard at home? Then it’s probably a UPF.

A word of warning: the front of pack traffic light indicators won’t tell you if a food is ultra-processed – you need to check the small print.

When was the last time you poured some ‘interesterified oil’ into a pan, or added a dash of maltodextrin to your recipe? Probably never, I’m guessing. Likewise for invert sugar, dextrose, lactose, soluble fibre, insoluble fibre. All these additives are designed to make food more palatable and as such they’re known as ‘cosmetic additives’.

Certainly some of these additives occur naturally in whole foods, but this doesn’t make them the same as eating them as part of those whole foods. For instance, lactose occurs naturally as the sugar found in milk. But removing it from its natural ‘food matrix’ and then adding it back as an extra ingredient makes our bodies respond to it differently and turns it from natural to ultra-processed.

Then there are all the other additives that go to make a food ultra-processed, such as bulking, gelling, carbonating, anti-foaming and glazing agents. Or sweeteners, thickeners, flavour enhancers, colours and emulsifiers.

Sadly for parents, it’s not just the obvious ‘junk food’ candidates that contain these ingredients. For example, if you buy supermarket bread you’re almost certainly buying a UPF. This label provides an example of what you and your children might be eating.

Bear in mind, this is a label from a premium supermarket loaf marketed as ‘made with wholemeal wheat flour, wholemeal spelt flour and sunflower seeds’. Sounds healthy, doesn’t it? In fact, foods marketed with health claims might be the ones you need to watch out for the most. Back in 2008, Michael Pollen wrote “In Defence of Food”, talking about ultra-processed foods as “edible foodlike substances” and he went so far as to say, “a health claim on a food product is a strong indication it’s not really food”.

And the front of pack traffic light indicators won’t tell you if a food is ultra-processed – sadly, you need to check the small print.

I know that many children, and particularly fussy eaters, are not going to be happy about making changes. So choose the easiest swaps first and take a look at some techniques designed to help children accept new foods - How can I get my child to eat vegetables?, Four tips to make family meals happen and Tips to tackle fussy eating for the year ahead.

Could my child's brain be affected forever?

The biggest worry for parents whose children eat UPFs, will be seeing the brain scans in the programme and wondering if this means that your children are wired to eat unhealthily for life. We simply don't have enough evidence to know definitively whether or not this will be the case. But again, my own experience here would suggest that children and adults alike can change their diets and learn to eat a greater balance and variety of food. There is evidence for this from research into fussy eating. And I’ve done some quick research since the programme ended last night to see if there’s any scientific evidence at all that could point to the potential for reversing changes to the brain from eating UPFs.

There is clearly so much research that is still needed, not just to understand the damage that UPFs do to us – but how to undo the damage that they’ve already done.

I looked into the neuroscience evidence around the effects of mindfulness on the brain of addicts – because that is effectively how Dr van Tulleken’s brain was behaving. It turns out that some limited evidence does exist and that it’s positive. Mindfulness treatments for addicts seem to result in a strengthening of the pre-fontal cortex’s control networks so that reward processing, cue-reactivity and stress reactivity can all be better controlled. Evidence for ‘mindful eating’ practices also shows that they are effective in addressing binge eating, emotional eating and eating in response to external cues. This offers hope that there is potential to reverse some or all of the effects of UPFs on our brains over time.

Something else that wasn’t covered in the BBC programme, but is another thing that could be implicated in Dr van Tulleken’s symptoms and changes, is an altered gut microbiome. The relationship between the gut and the brain isn’t fully understood, but it’s thought that gut microbiota can affect the release and functions of gut hormones – including the fullness and hunger hormones identified in the documentary as having changed as a result of the UPF diet.

Current thinking is that the better the diversity of the bacteria in our guts, the better our gut health, and the better it functions to support our overall health. I don’t know about any large-scale studies on this, but Professor Tim Spector did a similar one-man study to Dr van Tulleken's some years ago – only this time on his son Tom (aged 22 at the time)! Tom Spector ate a fast-food diet for 10 days, during which time he lost 40% of the detectable species in his gut microbiome – and it remained depressed ‘for a couple of years’. Although it did eventually recover. Again, this offers another avenue for hope and a possible explanation for how some people can make a long-lasting transition away from ultra-processed foods and rebalance their fullness and hunger hormones over time.

There is clearly so much research that is still needed, not just to understand the damage that UPFs do to us – but how to undo the damage that they’ve already done. If you’re a parent who watched the documentary and felt despair at the prospect of ever helping your child to eat a healthier diet, then I hope this article has pointed to some brighter spots on the horizon.

The current food system is fantastically challenging for parents and there is much that is outside our control. But the last thing I would want any parent watching that programme to feel is disempowered or hopeless - change is possible. It might not be quick and easy to do, but your child's diet is not a lost cause.


Sarah is a family health coach with a specialism in children's fussy eating. She offers one-on-one and small-group coaching to parents who want to change what their family eats for the better. If you think Sarah might be able to help you with your child's eating, please get in touch and ask for a free initial consultation.


Garland, Eric L, and Matthew O Howard. “Mindfulness-based treatment of addiction: current state of the field and envisioning the next wave of research.” Addiction science & clinical practice vol. 13,1 14. 18 Apr. 2018, doi:10.1186/s13722-018-0115-3

Pollan, M (2008) In Defence of Food. Penguin, London

Sun, Li-Juan et al. “Gut hormones in microbiota-gut-brain cross-talk.” Chinese medical journal vol. 133,7 (2020): 826-833. doi:10.1097/CM9.0000000000000706

Spector, T (2020) Spoon-Fed, Why Almost Everything We've Been Told About Food is Wrong, Jonathan Cape, London

Warren, Janet M et al. “A structured literature review on the role of mindfulness, mindful eating and intuitive eating in changing eating behaviours: effectiveness and associated potential mechanisms.” Nutrition research reviews vol. 30,2 (2017): 272-283. doi:10.1017/S0954422417000154

Wilson, B (2015) First Bite, How We Learn To Eat. 4th Estate, London

Wilson, B How ultra-processed food took over your shopping basket, The Guardian, February 2020 https://www.theguardian.com/food/2020/feb/13/how-ultra-processed-food-took-over-your-shopping-basket-brazil-carlos-monteiro