The surprising reason UPFs are bad for us – and the one hack to make them healthier

Could we have misunderstood why junk food is bad for us all along? Processed food, like ready meals and snacks, is usually seen as unhealthy because of its high fat and sugar content and artificial ingredients.

But the real reason could be that processed food tends to be softer, and so is eaten more quickly than its whole-food equivalents, experts heard at a conference last week.

That softer texture means people manage to eat more calories before they feel full. And that could be why people who eat more ultra-processed food (UPF) tend to be more overweight, which worsens a host of health conditions.

A study showed that people on a diet of UPF that was designed to take longer to eat had fewer calories per day than those in a comparison group eating regular UPF.

“If you have softly textured, energy-dense foods that are very easy to consume, then by the time you realize you’ve over-consumed, it’s too late,” said Professor Ciarán Forde, a food scientist at Wageningen University in The Netherlands, who led the research.

UPF is defined as food that has been altered or processed in any way, and so includes foods that may usually be seen as relatively healthy, including sliced bread, breakfast cereals, pre-prepared sauces and flavoured yoghurts.

‘Slow’ vs ‘fast’ UPF

Forde’s team designed two different UPF diets that were broadly similar, but one was designed to encourage faster eating than the other.

A group of 41 Dutch people were given all their meals and snacks for two weeks on one diet, then after a break, tried the other diet for two weeks. They could eat as much as they wanted of the provided foods.

The study compared two different diets – one encouraged faster eating than the other, but both were mainly UPF. Typical menus were:

‘Slow’ UPF diet

Breakfast: Yogurt, high-fibre cereal with fruit chips.

Lunch: Cheese sandwich with multigrain bread.

Dinner: Smoked chicken breast slices, prepared mixed salad and pre-cooked flavoured rice.

‘Fast’ UPF diet

Breakfast: Fruit smoothie and brioche.

Lunch: Cheese sandwich with soft bread.

Dinner: Ready-meal meat stew with mashed potatoes.

While on the “slow” diet, people consumed 370 calories fewer per day than when eating the “fast” diet, the trial found. For context, people are supposed to eat about 2,000 calories a day.

“Energy intake rate influences the amount of calories that we consume in a meal,” said Professor Marlou Lasschuijt, a food scientist at Wageningen University who also ran the trial, while presenting the results at the British Nutrition Foundation’s conference last week, Beyond the UPF Debate.

The results suggest that people don’t need to cut out all processed food to eat healthily, said Forde. The meals in the slow diet “were not specially constructed foods – these are foods from the local supermarket. We just looked at how they were eaten rather than what was in them.”

The hack: Slow-food movement

Professor James Stubbs, a biopsychologist at the University of Leeds who was not involved in the study, said more research was needed into which “slower-eating” foods have more appeal.

“Understanding this in a more nuanced way would help us steer people towards the more textured foods that are slower foods, and are better for weight management,” he said.

“You don’t have to go out of your way to make every food you eat incredibly crunchy and dry and unpleasant and thick and chewy and hard,” said Forde.

Pointing to the food he provided the trial participants, he said: “There are very simple swaps that people can make that can actually change the way they eat and slow it down.”

He added, however, that food texture and eating rate are unlikely to be the only factors that make UPF less healthy. “I would never say there’s a single cause for something as complicated as human behaviour.”

المصدر: iNews