Not all calories are created equal: how ultra-processed foods are ruining our health
Why do we snack on pastries or potato chips rather than fruit or nuts, even when we know they’re bad for our health?

How you handle that mid-afternoon energy lull will say a lot about your underlying health. If, like many people, you regularly reach for a packaged sweet, or a savoury snack then you’ll be fuelling inflammation rather than your energy levels.

Such habits are dangerous because the damage isn’t immediately apparent. But over the years, chronic low-level inflammation prompts faster ageing and all manner of illnesses from Alzheimer’s to diabetes and cancer to cardiovascular disease.

Over the past decade, there’s been a lot of research into why we don’t gravitate towards healthier options. And the conclusion’s pretty clear. Many people have become addicted to ultra-processed foods that are scientifically engineered to light up the reward part of our brain and trigger a primal desire for the kind of calorie density that helped our ancestors survive when food was scarce.

The term ultra-processed food first came into the spotlight in 2009 when the Brazilian scientist Carlos Monteiro suggested that it’s just as important to consider how much a food has been processed, as its headline nutritional value.

Ultra-processed foods are especially harmful because of their industrial processing and long list of ingredients, which don’t have a natural home in the kitchen cupboard. They’re factory formulations of additives, synthetic flavourings, industrial oils and preservatives.

They score low on nutritional value and are chock-full of sugar, salt and hydrogenated fats. Examples include ready meals, pizzas, cakes, salty snacks and carbonated drinks.

What makes them so addictive? Well firstly, there’s the dopamine hit they generate and secondly, food scientists have designed them to be hyper-palatable. Who doesn’t enjoy the smoothness of a piece of chocolate on their tongue, or the crunchiness of a salted bite?

All these sensations have all been artificially enhanced to make us want more.

And yet, the short-term pleasure doesn’t satisfy us for long despite the label’s high calorie count. That’s because ultra-processed foods have also been designed to be rapidly chewed, swallowed and absorbed: far too rapidly for our guts to tell our brains that we’re full.

Multiple studies also show that as countries move up the income scale, their populations rapidly develop a taste for these foods. Richer and more educated urbanites in middle-income countries eat far more ultra-processed foods than their rural counterparts who may be poorer but often have a healthier diet.

One reason is that time-poor, office-based workers have the income but not the inclination to cook for themselves and often their children too. Over time, they lose the ability to prepare a meal from scratch as well.

Covid-19 has made the situation far worse. The rise of home deliveries and desire for treats to counter pandemic-induced gloom is neither good for our waistlines, nor our biological ageing.

Over the past few years, affluent consumers in high-income countries have become more aware of the dangers. However, poor food choices are still being made.

Some people have given up, or cut down on, meat for ethical, planetary or health reasons, for example. Yet while the new plant-based and vegan foods sound healthy, that’s typically just the labelling. Meatless burgers and fishless fillets are often highly processed.

Here’s a few examples of what ultra-processed foods are doing to our health and some tips to counter their siren call:

1. Obesity

One of the most famous studies examining the links between ultra-processed foods and weight gain was published in 2019.

It divided healthy adults (average age 30), into two groups and kept them in a research facility for a month. Both groups were given meals with the same number of calories, carbohydrates, fat and sugar.

One group had ultra-processed and the other a minimally or unprocessed meal for breakfast, lunch and dinner for the first two weeks before switching to the other for the final two. Each group could eat additional snacks if they felt hungry. The researchers discovered that when participants were on the ultra-processed diet, they consumed an additional 500 calories per day.

It’s therefore, not surprising that countries with high levels of ultra-processed food consumption struggle with obesity. In the UK, these foods account for 57% of energy intake and in the US, 67% among adolescents.

So what can we do? Ultra-processed foods can be hard to resist at the end of a tiring and stressful day. One option is to do something else when snack time hits – a quick walk around the block, or phone a friend.

Likewise, batch cooking then freezing is the healthy ready meal alternative to the industrially processed supermarket variety.

2. Microbiome disruption

We may feel like individuals, but we accommodate trillions of microorganisms living inside us. These beneficial bacteria perform a multitude of functions from boosting the immune system to dampening inflammation.

However, they can start eating into the mucosal layer, which lines our colon, if we don’t feed them properly. Bacteria that breaks through this barrier into the bloodstream prompts inflammation and a host of chronic diseases.

Ultra-processed foods also offer our microbiome little nutritional value and don’t help to form bigger colonies of beneficial bacteria either.

So why not feed bacteria the food they need. Topping the list are prebiotics, a type of fibre that passes through the gastrointestinal tract intact until the bacteria get to feed on it. Examples include: oats, barley, rye, nuts, onions, garlic and leeks.

3. Non-communicable diseases

While it’s well known that chronic inflammation causes many health issues, the links between food, inflammation and certain diseases have only recently been established.

In 2018, a French study calculated that a 10% increase in ultra-processed foods led to a greater than 10% risk of cancer.

A second French study also concluded that a similar increase in ultra-processed foods led to a 12% increase in cardiovascular and 13% increase in coronary heart disease rates.

4. Mental illness and neurological disorders

Mental health is a complex issue. However, there’s increasing research linking mood swings, anxiety and depression to diet. One Spanish study demonstrated that the participants who ate the most highly processed foods had the highest rate of depression.

Brain disorders such as epilepsy, ADHD (attention deficit hyperactivity disorder) and autism have also all been linked to diet and an unbalanced microbiome.

The brain needs the right nutrients to function, while gut bacteria produce many of the neurochemicals regulating mental function. For instance, the gut produces 95% of the mood stabiliser serotonin.

The message is clear: we shouldn’t think of food in terms of calorie in, calorie out. How calories are produced and the nutrients they provide are both key to our long-term health.


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