Scientists have successfully developed an ingredient that can be added to foods to make people feel full and also prevent weight gain.
Researchers at Imperial College London and the University of Glasgow found that in its first tests in humans the ingredient was effective at preventing weight gain in overweight volunteers.
The ingredient contains propionate, which stimulates the gut to release hormones that act on the brain to reduce hunger.
Propionate is produced naturally when dietary fibre is fermented by microbes in the gut, but the new ingredient, called inulin-propionate ester (IPE), provides much larger quantities of propionate than people can acquire with a normal diet.
In the study, 20 volunteers were given either IPE or inulin, a dietary fibre, and were allowed to eat as much as they liked from a buffet.
Those given IPE ate 14 per cent less on average, and had higher concentrations of appetite-reducing hormones in their blood.
Next, 60 overweight volunteers took part in a 24-week study in which half were given IPE as a powder to add to their food and half given inulin. One out of 25 volunteers given IPE who completed the study gained more than three per cent of their body weight, compared with six out of 24 given inulin.
None of the IPE group gained more than five per cent of their body weight, compared with four in the inulin group.
After 24 weeks, the IPE group also had less fat in their abdomens and livers compared with the inulin group.
"We know that adults gain between 0.3 and 0.8 kilos a year on average, and there's a real need for new strategies that can prevent this," said Professor Gary Frost, who led the study at the Department of Medicine at Imperial College London.
"Molecules like propionate stimulate the release of gut hormones that control appetite, but you need to eat huge amounts of fibre to achieve a strong effect. We wanted to find a more efficient way to deliver propionate to the gut.
"This small, proof-of-principle study shows encouraging signs that supplementing one's diet with the ingredient we've developed prevents weight gain in overweight people. You need to eat it regularly to have an effect.
"We're exploring what kinds of foods it could be added to, but something like bread or fruit smoothies might work well," Frost said.
The findings are published in the journal Gut.
