BBCTV presenter Dr Chris van Tulleken challenged himself to eat a diet made up of mostly ultra-processed foods for a month.
Over half the energy from food eaten in the UK is believed to come from ultra-processed products. There are concerns these foods lead people to eat more and put on weight. One in four adults in the UK is estimated to be obese, as well as one in five children aged ten to eleven.
“I wanted to find out what effect a diet high in ultra-processed food had on me”, says Dr Chris Van Tulleken, presenter of What are we Feeding our Kids? (BBC One Thursday 27 May 9pm). There is little research on how ultra-processed foods interact with our bodies, especially among children and teenagers, who eat more than the average adult.
For the experiment, Chris increased his usual intake of 30 percent ultra-processed foods to 80 percent for four weeks. “It sounds extreme, but it’s the diet one in five people in the UK eat”, he says.
‘I felt ten years older’
Chris ate a diet made up of 80 percent ultra-processed foods, the same diet that one in five Brits eat, according to Chris.
After the month was over, Chris reported poor sleep, heart burn, unhappy feelings, anxiety, sluggishness, and a low libido. He also had piles from constipation. “I felt ten years older”, he says, but “didn’t realise it was all [because of] the food until I stopped eating the diet”.
Chris gained almost 7kg in the four weeks and moved from a healthy weight to overweight. “If the weight gain continued at that rate for six months, I would have gained six stone”, he says. It didn’t stop there.
Brain activity scans showed the areas of Chris’ brain responsible for reward had linked up with the areas that drive repetitive, automatic behaviour. “Eating ultra-processed food became something my brain simply tells me to do, without me even wanting it”, he says, adding this is a similar brain response to taking substances we consider classically addictive such as cigarettes, alcohol and drugs. The changes in brain activity weren’t permanent, but “if it can do that in four weeks to my 42-year-old brain, what is it doing to the fragile developing brains of our children”, he says.
We don’t know exactly why ultra-processed foods have these effects, but Chris says most hypotheses come down to a combination of the physical act of processing and their nutrient make-up.
Impact on how much we eat
Chris talks to Dr Kevin Hall, a senior investigator for the National Institute of Health, on the documentary. For research, Dr Hall tested two diets that were matched in terms of fat, sugar, salt and fibre content, but one was made up of unprocessed foods and the other of around 80 percent ultra-processed foods. The participants were able to eat the foods on offer until they wanted to stop.
His study found “folks eating the ultra-processed diet ended up eating more than 500 calories per day more [and] gained almost a kilo of body weight over two weeks”, says Hall. Blood tests showed an increase in the hormone responsible for hunger and a decrease in the hormone that makes us feel full among the participants eating the diet high in ultra-processed foods. These results were consistent with Chris’ experience – his hunger hormone increased by 30 percent during his experiment, which may have encouraged over consumption.
Hall also found participants on the ultra-processed diet ate much more quickly than those on the minimally processed diet, which may have contributed to the consumption of more calories. Chris experienced this too, as many of the “foods are so easy to chew and swallow”. Previous studies have suggested eating slowly decreases hunger.
‘It’s really hard to stop eating’
“I found myself craving food much more often”, says Chris. Research has previously found some foods, including ultra-processed pizzas, chocolate, crisps and cakes, can elicit cravings, loss of control, and inability to cut back.
There is evidence foods high in carbohydrates and fat (as many ultra-processed foods are) can trigger the centres of the brain responsible for reward, emotion and motivation. A brain imaging study suggests the more often you experience reward from foods, the more you have to consume to sustain the same enjoyment.
Many ultra-processed foods have also gone through focus groups to make them ‘perfect’. The taste, level of saltiness, mouthfeel, chew, and even the sound it makes when eaten, may have been fine-tuned. “I don’t think anyone at any food company set out with the intention of making people gain weight”, says Chris, adding a “side-effect of really delicious food is that it’s really hard to stop eating it”.
Should we avoid all ultra-processed foods?
Foods can be categorised as minimally or unprocessed (for example, tomatoes), processed (tinned tomatoes) and ultra-processed (store-bought tomato pasta sauce). Some ultra-processed foods are healthier than others – wholegrain breakfast cereals, wholemeal sliced bread, tinned baked beans, and unsweetened soy or plant-based drinks, are all ultra-processed but have nutritional benefits. Similarly, ready-made pasta sauces, ready meals, spreads and sliced meats can be healthy.
Some pre-prepared foods are not ultra-processed, but any that include additives and chemicals not used in home cooking probably are. The availability, convenience and marketing of ultra-processed food makes it “almost impossible” to eliminate, says Chris.
Although a diet high in ultra-processed foods is not recommended, eating them on occasion is unlikely to cause a risk to health, according to dietitian Ro Huntriss. “Having a healthy diet is all about balance”, she says.
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FAQs
For his experiment, Chris ate a diet made up of 80 percent ultra-processed foods, the same diet one in five Brits eats, according to Chris. After the month was over, Chris reported poor sleep, heart burn, unhappy feelings, anxiety, sluggishness, and a low libido. He also had piles from constipation.
What happened when a doctor only ate ultra-processed foods for a month? ›
And then in the evening, I had a lot more convenience foods. I'd have microwavable lasagna, or I'd have takeaway fried chicken or pizza. AUBREY: Within a month, he says he'd gained a bunch of weight, which isn't much of a surprise. All the sugar and refined carbohydrates can drive up appetite.
What are the long term effects of ultra-processed foods? ›
They found “convincing evidence” that higher ultra-processed food intake was associated with about a 50 percent increased risk of cardiovascular disease-related death, a 48 to 53 percent higher risk of anxiety and common mental disorders, and a 12 percent greater risk of Type 2 diabetes.
What happens if you only eat ultra-processed food? ›
Several studies have shown that eating higher amounts of ultra-processed foods is linked to a greater risk of: high blood pressure. cardiovascular disease. heart attacks and strokes.
What happens if you eat processed food everyday? ›
In the long term, eating too much processed food can lead to high blood pressure, diabetes, cancer, obesity, and “brain fog” or other reductions in cognitive abilities. Shapira suggested eating a minimum of four servings of fruits and veggies every day. That can include frozen and canned veggies.
What happens if you eat junk food for a month? ›
Excess calories from fast food meals can cause weight gain. This may lead toward obesity. Obesity increases your risk of respiratory problems, including asthma and shortness of breath. The extra pounds can put pressure on your heart and lungs, and symptoms may show up even with little exertion.
Will I lose weight if I stop eating ultra-processed foods? ›
The answer was a definite "yes." On the ultra-processed diet, people ate about 500 calories more per day, ate at a faster rate and gained weight. On average, participants gained 0.9 kilograms, or 2 pounds while they were on the ultra-processed diet and lost an equivalent amount on the unprocessed diet.
Is peanut butter ultra-processed? ›
You could just crush up peanuts and get peanut butter that's minimally processed. You could add salt, sugar, and oil and get a processed version. Or some of the peanut butter you find at the store could contain preservatives or emulsifiers, and that makes it ultraprocessed.
What do ultra-processed foods do to your brain? ›
Blood vessels in the brain
Previous research has shown that consuming ultra-processed foods is linked to an increased risk of cerebrovascular disease. This affects the blood vessels in your brain.
What is the alarming truth about ultra-processed foods? ›
“These types of foods have been linked to things like obesity, metabolic syndrome, certain cancers, and even mental health issues, like anxiety or depression,” Simkus said. If you are looking to eliminate some of these ultra-processed foods, Simkus said it's okay to start small.
1. Bacon
- Fried food. ...
- Potato chips. ...
- Added sugars. ...
- Processed oils. Try to cut processed oils out of your diet as much as possible. ...
- Hydrogenated fats. This category of fats lurks in many packaged foods and fast food products. ...
- Refined carbohydrates. Advertisem*nt. ...
- Breakfast sausages. Advertisem*nt. ...
- Processed meat. Advertisem*nt.
Here is a short list of some unhealthy processed foods to avoid:
- Sugary beverages such as sweetened coffee and tea, energy drinks and soft drinks.
- Deli meats, hot dogs and sausages.
- Frozen pizza and frozen meals.
- Packaged snacks such as chips, cookies, crackers and baked goods.
- Most breakfast cereals.
- Canned or instant soups.
If you base your diet on fruits, vegetables, pulses, grains and nuts, then you won't be eating a lot of UPF. Vegan alternatives to meat, including mushrooms, jackfruit, beans and tofu, are not UPF. However, “fake meat” – burgers, sausage, bacon etc – and most vegan cheeses are.
How long does processed food stay in your body? ›
After you eat, it takes about six to eight hours for food to pass through your stomach and small intestine. Food then enters your large intestine (colon) for further digestion, absorption of water and, finally, elimination of undigested food. It takes about 36 hours for food to move through the entire colon.
What are the most common ultra-processed foods? ›
Limiting processed foods is already something we know
| Ultra-processed | Processed |
|---|
| soda | artificially flavored sparkling water |
| flavored potato chips | plain tortilla chips |
| white bread | whole wheat bread with minimal ingredients |
| fried chicken | deli rotisserie chicken |
7 more rowsHeavily processed foods often include unhealthy levels of added sugar, sodium and fat. These ingredients make the food we eat taste better, but too much of them leads to serious health issues like obesity, heart disease, high blood pressure and diabetes.
What happens if you don't eat processed foods for a month? ›
Cutting out processed foods could lead you to experience a variety of personal health benefits such as having more energy, losing weight, improving regularity, or just feeling healthier overall.
What diseases can be caused by an ultra-processed food diet? ›
The researchers said they found an association between ultra processed foods and all causes of mortality, breast cancer, colorectal cancer, pancreatic cancer, adverse sleep outcomes, adverse anxiety outcomes, asthma, hypertension, Crohn's disease, ulcerative colitis, obesity, metabolic syndrome, non-alcoholic fatty ...
What does ultra-processed food do to the brain? ›
Blood vessels in the brain
Previous research has shown that consuming ultra-processed foods is linked to an increased risk of cerebrovascular disease. This affects the blood vessels in your brain. The Brazilian study found links between ultra-processed foods and executive function.
How much does consumption of ultra-processed foods may up dementia risk? ›
After adjusting for age, sex, high blood pressure and other factors that could affect risk of dementia, researchers found that a 10% increase in the amount of ultra-processed foods eaten was associated with a 16% higher risk of cognitive impairment.
