The ultra-processed foods to avoid (and what to eat instead)

It’s no secret that fast foods are a major factor in the obesity epidemic in Australia, but new research shows they can also damage mental health.

A new study by Deakin University’s Food & Mood Centre has found people who eat higher amounts of ultra-processed foods (UPFs) have a 22 per cent greater chance of developing depression.

“Ultra-processed foods have already been linked to poor health and early death, but this is the first time they’ve been proven to lead to the development of depression, taking two to 10 years to develop,” says researcher Melissa Lane, who worked on the study that combined results of two large studies of 41,000 adults in Spain and France.

“There’s really strong evidence that eating in a healthier way with minimal processed foods is linked to better mental health and a reduction in depression.”

What are ultra-processed foods?

UPFs are highly refined, industrial formulations. They contain little, to no, whole food and many food additives so they have little resemblance to simple, much healthier, minimally processed foods.

For example, highly refined and mass-produced bread made from complex ingredients and food additives never or rarely used in kitchens including emulsifiers, preservatives and colourings may be more harmful than bread made simply from flour, water, salt and yeast.

So bread is still a processed food, but Melissa says it’s not as harmful as ultra-processed varieties that may negatively affect the gut microbiome.

How ultra-processed foods affect mental health

“One of the main problems with UPFs is that they are linked to inflammation, affecting the gut microbiome and its role in likely inflaming the whole body,” Melissa says.

“Depression is largely considered an inflammatory disease but these foods are also linked to obesity, metabolic syndrome, cardiovascular diseases, cancer, irritable bowel syndrome and respiratory diseases, which all have inflammation as part of their clinical picture.”

Physical risks of ultra-processed foods

Deakin’s Institute for Physical Activity and Nutrition research fellow Dr Priscila Machado has been studying UPFs for many years, specialising in obesity.

“Our studies have shown that people who eat UPFs are 61 per cent more likely to be obese than the 20 per cent who eat less,” Dr Machado says.

Australians eat an average of 42 per cent of their calories from ultra-processed foods a day, says Dr Machado.

“In people who eat more of them, that figure rises to 75 per cent and those who eat less would have 20 per cent of UPFs in their diet. But even people eating 30-40 per cent of these foods have a higher risk,” she says.

How ultra-processed foods fool you into eating more

Chemicals in UPFs are engineered to prevent satiety so they are easy to overeat.

“These foods are easier to chew and swallow because they’re very soft in texture so you can eat a lot of them without noticing,” says Dr Machado.

“They’re also hyper-palatable and energy dense so that sends a message to our brain to not stop eating them, making them more addictive.”

What to eat instead of ultra-processed foods

Swap: Energy drinks

Energy drinks contain excessive caffeine, sugar and modified substances. Swap for home-brewed coffee or tea with little added sugar.

Swap: Packaged biscuits and snacks

Homemade treats will contain much less sugar, salt and fat without additives.

Swap: Flavoured yoghurt

Flavoured yoghurt contains high levels of sugar and additives. Instead, eat natural or unflavoured Greek yogurt.

Swap: Pre-prepared marinated meat, sausages, hot dogs and meat alternatives

These are formulations of industrial ingredients, containing a high amount of salt, flavours and colours. Swap for legumes or unprocessed meat that you can marinate at home.

Swap: Ready-to-eat frozen pasta dishes

Go for dried pasta instead made with fresh ingredients.

Swap: Fruit drinks, iced tea, soft drink

Drink plenty of water, eat fruit in its original state or make your own fresh fruit juice.

Written by Catherine Lambert.