When we think about food and health, we often focus on nutrients; protein, carbs, fats, vitamins. But food is far more complex than that. It contains over 70,000 different compounds, all interacting in ways that impact our health. The structure of food (the food matrix) and non-nutritive compounds play a massive role; meaning a food’s health effects can’t be judged by nutrients alone. Processing changes food’s structure, altering how our bodies respond.
It is theorised that this is why we see an increase in chronic disease with an increased consumption of ultra-processed foods (UPF). The processing our food goes under to turn it into UPF often destroys this food matrix and removes many of the non-nutritive compounds which are protective against chronic disease. This may also explain why some UPF’s are not associated with increases in chronic disease; their food matrix isn’t altered. Let’s talk about it.
The Issue With UPF Research
According to the NOVA classification, UPFs are linked to a worrying range of health issues—poor mental health, cardiovascular disease, cancer, and even premature death. Studies suggest that for every 10% increase in UPF consumption, all-cause mortality rises by 2.7%.
The reality is, however, NOVA was never created to be applied to identify how healthy a food is. It was simply a way for researchers to identify the level of processing a food has. Because of this, many foods which are actually healthy are lumped into the same category as others which aren’t; wholegrain bread, breakfast cereals, and plant-based alternatives, may actually lower mortality risk, and this has been shown in research. It’s not a perfect system and was never intended to be used in the way we have started to apply it.
One other issue with the definition of UPF and food and nutrition research is that the same product could be UPF or non-UPF depending on how it was made, and this is very rarely ever ascertained in any research on UPF food and disease risk. Take peanut butter for example; you can have one made of simply peanuts and salt, and another with additional sugar, oils, emulsifiers, stabilisers and other additives. These two are obviously very different and would likely cause different outcomes in research results; but they are often lumped together and no distinction is made between the two.
The reality is, NOVA doesn’t make much sense to identify whether something is healthy or not. Foods which are high in fat, sugar, salt and calories can be non-processed, and foods which are low in these, high in fibre and associated with a reduced risk of mortality and diet-related conditions can be considered UPF. 15-20% of NOVA 4 foods (ultra-processed) could still be healthy, while 50% of foods with four ‘red’ traffic lights might be minimally processed. NOVA is not the best way to assess the impact of a food on our health or wellbeing.
Despite This, There Is Some Support for Reducing UPF
A randomised controlled trial undertaken in 2019 (Hall et al.) compared UPF vs. non-UPF diets, matched for macros. Participants were in a controlled environment, and given either a fully UPF diet or fully non-UPF diet, and asked to eat until they were full each day. After just two weeks, the UPF group:
✔ Gained 2kg
✔ Ate 508 extra kcals/day
✔ Ate 50% faster
This does suggest there is something in common between foods which are UPF. When we consider the fact that the UK diet is approximately 55% UPF, which has been increasing over the years, and correlates with an increase in our waistlines, perhaps there is something within foods which can be UPF which do cause weight gain?
What it is Within Certain UPFs Which May Be Causing Our Health Problems
We know that not all UPFs are associated with an increased risk of disease, obesity, and increased mortality, and these foods (breads, wholegrain cereals, plant based products) all have a few things in common.
- They do not have an increased energy density.
- They do not have a broken down food matrix.
- They are not hyperpalatable.
- They provide essential, key nutrients which many people lack.
We can infer from this that possible reasons some UPF’s are associated with an increase in disease and mortality include:
✔ Altered food composition: fewer healthy nutrients, more additives such as emulsifiers and stabilisers.
✔ Higher energy density: UPF’s have 40% more calories per gram than non-UPF’s.
✔ Hyper-palatability: causing faster eating, more overconsumption.
✔ Destroyed food matrix: affects digestion, blood sugar, and hunger hormones.
The Matrix Matters: Why Whole Foods Keep You Fuller
Ever noticed you feel hungrier 2-4 hours after a smoothie than after whole fruit? Blame the food matrix. Blending or juicing destroys cell structures, speeding up digestion and reducing fullness hormones (GLP-1, PYY).
Even nut calorie counts are misleading—you absorb 130kcal from nuts vs. the 162kcal on the label! Particle size also affects blood sugar, insulin, and fat absorption.
The Bottom Line
UPFs aren’t equal. Many foods considered UPF are considered to be health promoting and reduce your risk of many diseases, whereas others do increase mortality and disease risk.
We need more nuance in the UPF discussion. We cannot keep relying on the NOVA classification to provide us with the guidance as to what is a better and more nutritious food choice.
To be honest, a lot of it is common sense. Foods which are hyperpalatable (burgers, pastries, crisps, sauces, sweets, cakes etc) increase our risk of disease. Foods which aren’t, don’t. We are overcomplicating this argument and it is something which could actually cause more harm than good.
What’s your take? Have you noticed how different foods affect your hunger? Let’s discuss in the comments!
A special thanks to Dr Sarah Berry for an insightful BDA study day lecture which provided the information for this post.
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