We hear the term “ultra-processed food” everywhere these days. But there is a problem: people often confuse processed food with ultra-processed food.
They are not the same thing.
Almost everything we eat has undergone some form of processing. Freezing peas is processing. Turning milk into cheese or yoghurt is processing. Tinned tomatoes, frozen vegetables, canned beans, olive oil and freshly baked bread have all been processed in some way.
Processing food isn’t automatically bad for us.
The important distinction is what happens when we move into ultra-processed foods, or UPFs.
These are generally industrially manufactured products made using ingredients and processes you wouldn’t normally use in your own kitchen. They can contain things such as modified starches, protein isolates, emulsifiers, flavour enhancers, colours, sweeteners and other additives.
Think fizzy drinks, confectionery, packaged cakes and biscuits, many fast foods, some breakfast cereals, instant noodles and numerous ready meals.
But even here we need some common sense. A product doesn’t suddenly become poisonous because it contains an emulsifier, and not every food classified as ultra-processed has the same nutritional value.
The bigger question is what happens when UPFs make up a large proportion of our diet.
What happens when we cut them out?
This is where the science is becoming fascinating.
In a controlled clinical trial published in Nature Medicine, researchers compared diets containing ultra-processed foods with diets based on minimally processed foods. Importantly, both diets were designed to follow healthy UK dietary guidelines.
People were allowed to eat until they were satisfied.
After eight weeks, participants lost weight on both diets – but they lost approximately twice as much weight on the minimally processed diet.
They also lost more body fat and experienced a greater reduction in food cravings.
Previous controlled research has produced another interesting finding: when people are offered ultra-processed foods, they tend to consume more calories.
In other words, it may not simply be a question of willpower.
The characteristics of the food itself – how quickly it can be eaten, its texture, energy density, palatability and combination of ingredients – may make it easier to consume more energy before our body’s appetite signals tell us we’ve had enough.
There is now intriguing evidence that reducing UPFs could affect more than our waistline.
A small clinical study published this week looked at 20 people with depression who normally ate a diet high in ultra-processed food.
When participants switched to a diet containing dramatically less UPF, researchers reported moderate to large improvements across three measures of depression, while anxiety scores also improved modestly.
That’s exciting – but let’s not get carried away.
This was a tiny preliminary study. It doesn’t prove that ultra-processed food causes depression or that changing your diet can treat it. Larger trials are needed.
And there is still genuine scientific debate about UPFs. Researchers have questioned whether some apparent effects of processing might actually be explained by differences in the nutritional composition of the foods themselves.
So what should we actually eat?
For me, the sensible message isn’t “never eat processed food again.”
That would be unrealistic and unnecessary.
Instead, look at what makes up the majority of your diet.
Build meals around recognisable foods: vegetables, fruit, beans and pulses, potatoes, wholegrains, nuts, seeds, eggs, fish, lean meat and dairy if you eat them.
Cook when you can. Use frozen and tinned foods when they’re convenient. And don’t panic because occasionally you fancy a packet of crisps, a biscuit or a ready meal.
Good nutrition isn’t about achieving dietary perfection.
But the emerging evidence suggests that moving our diets away from heavily ultra-processed foods and towards simpler, minimally processed foods may make controlling our appetite and weight easier – and could potentially bring benefits that extend well beyond the scales.
