Speaking at Food Manufacture's New Frontiers in Food and Drink conference sponsored by Lloyds Bank and Roythornes Solicitors in London last month, Gary Frost, professor of nutrition and dietetics at Imperial College London, described how the complex process of appetite regulation could be influenced.
“We are wired to eat, so trying to reverse that is incredibly difficult,” said Frost. However, he described trials between Imperial College and the University of Glasgow using the non-digestible dietary fibre inulin in human trials. These trials showed appetite and energy intake were suppressed by about 15% compared with control groups.
They weren’t directed at weight loss, but at developing an ingredient that could go into a wide variety of foods and prevent slow and insidious weight gain, which happens with 60% of the population, he noted.
While the initial results were positive, the mechanism was not entirely clear, said Frost. However, the very latest research using functional magnetic imaging studies also pointed to activation of certain areas of the brain which control appetite behaving differently when propionate inulin ester was produced in the colon, he added.
The main research project showed inulin helped stimulate hormones secreted in the gut, such as Peptide YY and Glucagon-like peptide-1, which have a role in appetite regulation. he added.
‘It’s a bit bizarre’
“What we have with dietary fibre [non-digestible carbohydrate, such as inulin] is a system, it’s a bit bizarre, you are not absorbing the nutrient in the small intestine, it's flowing through into the large intestine, where the microbiota do their job; they break them down in the main to short-chain fatty acids, which act as a fuel source.”
Frost added that if you can stimulate receptors in the colon which produce appetite reducing hormones with short-chain fatty acids, it might be possible to produce a mechanism for suppressing appetite.
To target them it is necessary to get a cheap system for food that actually gets to the colon, which isn’t an easy task, said Frost. Using inulin, this is what Imperial College is currently working on in conjunction with researchers from the University of Glasgow.