It sounds like something out of a junky Facebook advertisement, but it's actually peer-reviewed research: Scientists from Imperial College London and the University of Glasgow have developed a food additive that helps people feel full earlier. And, according to their study, the first in humans, it could help overweight people prevent additional weight gain and, in an unanticipated finding, also lose heart-damaging abdominal fat.
The additive, inulin-propionate ester (IPE), is made from propionate, a natural byproduct of the stomach's fermentation of dietary fiber. It is this chemical reaction that stimulates release of satiety hormones -- meaning hormones that signal to the brain that the body is full -- such as hormones peptide YY (PYY) and glucagon-like peptide-1 (GLP-1). It is well-established that a high-fiber diet contributes to weight maintenance and feelings of fullness. We typically generate propionate from a diet containing fiber, but IPE delivers more of the molecule by several magnitudes.
"Molecules like propionate stimulate the release of gut hormones that control appetite, but you need to eat huge amounts of fiber to achieve a strong effect," said the study's leader, Gary Frost, Ph.D., a professor in the Department of Medicine at Imperial College London, in a statement. "We wanted to find a more efficient way to deliver propionate to the gut."
The researchers conducted two small experiments, aimed at demonstrating the abilities of propionate in humans (previous studies were in mice) and looking specifically at the effect of consuming the molecule in this unnatural quantity.
In the first, 20 participants were given powdered IPE or a complete dietary fiber, inulin. They were then instructed to eat as much as they wanted from the greatest enemy of portion control: a buffet. Those who ingested IPE ate an average of 14 percent less than members of the inulin group.
In a second, longer-term experiment, 25 overweight participants supplemented their food with IPE, while a control group of 24 overweight participants supplemented with inulin, both over 24 weeks.
Since the average adult gains about a pound each year, the success of this study was measured in weight not gained -- as well as changes to fat composition. At the end of the six-month period, researchers measured the body weight and compositions of the participants using an MRI scanner. They found that 25 percent of the control group -- six people -- had gained 3 percent of their body weights, while 17 percent -- or four individuals -- had gained 5 percent. By contrast, only one of the 25 in the IPE group gained more than 3 percent of their body weight.
While the goal of the study was to prove that IPE prevented weight gain, the researchers found that the IPE group also lost a statistically significant amount of subcutaneous and visceral fat around the abdomen, meaning belly fat and fatty deposits around organs like the liver. Both types of abdominal fat are implicated as risk factors for heart disease and even some cancers.
Optimally, we would all eat less overall and more of foods high in fiber, but in a food environment best represented by the first experiment's buffet table, supplements like these may provide a more realistic option.