Researchers find a popular type of cereal bar could super-boost weight loss

Daily Mail​

17-05-2025

Protein bars offer a convenient way to manage hunger on the go, but they could also help fuel weight loss, new research has found.
Researchers from the University of Navarra found that people who ate protein bars boosted with collagen—a protein found in connective tissue—lost twice as much weight as those who didn't have them, despite consuming the same amount of calories.
Head researcher Dr Paola Mogna-Peláez said collagen is an accessible and inexpensive protein is that can keep you fuller for longer, and is an alternative to potent weight loss drugs, like Ozempic and Wegovy.
'Many weight loss drugs are very expensive,' Dr Mogna-Peláez said.
'We were interested in collagen because it is a protein that is cheap and easy to obtain and is not known to have any side effects.'
The researchers studied 64 overweight and obese adults, weighing around 13 stone on average, aged 20-65, over a 12-week period.
All of the participants were given healthy eating advice based on the Mediterranean diet—hailed for its menu of fruit, vegetables and wholegrains—before the study started.
Half of the volunteers were instructed to eat two chocolate-flavoured protein bars fortified with 10g of collagen a day, with a glass of water before lunch and dinner.
Both groups consumed the same number of calories.
The collagen, which was extracted from cows, was modified to help it absorb extra water in the gut.
'Crucially, collagen's structure can be modified to allow it to absorb extra water, which leads to it growing in size,' Dr Mogna-Peláez explained.
'We wanted to know if such a compound creates a feeling of fullness when it expands in the stomach, reducing appetite and leading to weight loss,' she added.
The adapted bars are available to buy in US supermarkets, the experts wrote.
Before the study started, the participants filled out a questionnaire about their appetites and underwent a range of body measurements and other baseline tests.
Participants were measured periodically throughout the study.
After 12 weeks, those who were eating two collagen-boosted protein bars a day had lost twice as much weight as the control group— roughly five pounds, compared to two and a half.
Researchers also found that the collagen group experienced a significant drop in blood pressure.
Those consuming collagen also lost more weight around their waist, dropping 2.8cm over 12 weeks.
They reduced their body mass index (BMI) score by 1.2 units and saw improvements in liver function.
The control group, meanwhile, only dropped by an average of 0.78 BMI units.
Collagen snack eaters were also seen to gain more muscle mass than the control group throughout the course of the experience.
The questionnaires also showed that the collagen reduced hunger throughout the day.
To confirm these results, researchers also monitored the participants' leptin levels—a hormone that induces the sensation of feeling full.
Over the 12 weeks, levels of the hunger-inducing hormone decreased in both groups, but leptin levels were higher in the collagen group at the end of the study.
In animal trials, researchers noted that collagen had a similar effect, significantly reducing levels of ghrelin, a hormone that stimulates appetite.
Dr Mogna-Peláez said: 'Our results indicate that, by swelling in the stomach, the collagen made the participants feel less hungry, which would have led to them eating less and so losing weight.
'Collagen may also have led to the participants building muscle and we know that muscle burns more calories than fat.
'It is also possible that collagen changes the make-up of bacteria in the gut, which may aid with weight loss and appetite control.'
It comes as research presented at the European Congress on Obesity in Malaga found that the effects of GLP-1 weight loss drugs like Ozempic are short-lived if patients do not maintain a healthy lifestyle after they stop taking the medication.
The study, by researchers at the University of Oxford, found that patients typically returned to their original weight within 10 months of quitting the jabs.
The lead researcher, Professor Susan Jebb, said: 'These drugs are very effective at helping you lose weight, but when you stop them, weight regains much faster than [after stopping] diets'.
She added that patients lack 'behavioural strategies' to stop them over-eating when they cease taking the drug.
Speaking at the conference, experts said the obesity crisis cannot be solved by weight loss jabs alone.
'It shouldn't surprise anyone if people regain weight having used GLP-1 drugs without seriously attempting to improve their lifestyle. Using GLP-1s is not the quick-fix which many users believe it to be,' Tam Fry, chairman of the National Obesity Forum, said.
Around two in three adults in the UK are currently obese or overweight, giving the country one of the highest obesity rates in Europe.
Last year, a sobering report also suggested Britain's obesity crisis has fuelled a staggering 39 per cent rise in type 2 diabetes among young people under 40, with 168,000 Brits now living with the condition.
Overweight and obesity has also been linked to at least 13 types of cancer and is the second biggest cause of the disease in the UK, according to Cancer Research UK.