featured in this issue - NZIFST - The New Zealand Institute of Food ...

NUTRITION
Feeling fuller longer
Carl Massarotto, Plant & Food Research
This article is taken from Carl’s paper presented at NZIFST
Conference in June
Imagine a new class of diet product where the ingredients didn’t
just contain fewer calories, but actually kept you feeling fuller for
longer. Where that ‘I’ve eaten and I feel satisfied’ message lasted
longer – and yes, your gut really does signal your brain when it’s
had enough.
The feeling is called ‘satiety’ and it’s the focus of the Plant & Food Research
programme launched last year with R&D investment from the
government and some of New Zealand’s most well known food companies
including ZESPRI, Sanitarium, Hansells Food Group, Comvita
and NZ Extracts.
Foods for Appetite Control is a six-year research programme that began
in October 2010, aiming to expand on the current understanding
of how individuals ‘feel full’ and identify the precise compounds
responsible. It is anticipated that by examining the mechanisms responsible
for the sensation of ‘fullness’ that new whole foods, natural
ingredients and processed food products may then be developed to
trigger these sensations when eating earlier and for longer.
“We’re looking at what happens in the body to minimise the ‘I’m
hungry’ message,” says Dr John Ingram, a scientist in Plant & Food
Research’s Food Innovation Portfolio. “Then develop new natural ingredients
and whole foods that signal the same messages in the body
with far fewer calories.”
Feeling fuller for longer after eating, or satiety, is an important part of
dietary energy management and maintaining a healthy body weight.
It also has a role in offsetting issues including obesity, diabetes type 2,
cardiovascular disease and cancer, which are costly to individuals and
society at large.
The World Health Organisation (WHO) has suggested that there are
currently 1.6 billion overweight adults around the world and that more
than 700 million of these are obese. Not surprisingly this has led to
dramatic growth in the diet and weight management foods market, a
market now worth in excess of $513 billion globally. While the current
research programme is only in its early stages it is hoped that the results
may offer great opportunities for New Zealand food and beverage
manufacturers.
However, the “keeps you fuller longer” marketing message is nothing
new. Low glycemic index (GI) foods have been advertised for a
number of years as a means of staving off hunger. The message from
nutritionists and health professionals rings out strong with instructions
to eat more fruits, vegetables, pulses, wholegrains and other low GI
foods in order to prolong the release of glucose in the body and keep
us from feeling hungry for longer.
So is the Foods for Appetite Control research any different? Well, yes.
While it’s agreed that being told to eat more fruits and vegetables is
absolutely sound advice, scientists are taking a closer look at why these
foods elicit the response they do.
Dr John Ingram, a scientist in Plant & Food
Research’s Food Innovation Portfolio
It is already proven that the gut wall makes use of a range of sensory
cells (including taste receptors the same as our tongues’) to identify the
nutrients in the food we eat. However recent research now indicates
that some specific compounds initiate a much greater signal response
to the appetite control centres in the brain than others.
‘‘There are a number of these feedback mechanisms operating in the
digestive tract’’ says Ingram. ‘‘Different compounds act in different
ways depending on where in the system they have reached. If we can
get particular compounds to these specific target areas of the gut, the
person eating will feel the satiety effect for longer while having eaten
less”.
Researchers at Plant & Food Research are working to identify the naturally
occurring phytochemicals and carbohydrates in fruits, vegetables
and grains that affect appetite control signals from the digestive tract.
However, looking beyond basic nutrition to better understand the interactions
of our diet is not a simple task. The research is examining a
wide range of complex interactions, including both the chemosensory
function of the GI tract in modulating satiety and the role of phytochemicals
and carbohydrates as bioactives.
But why look at plants for new appetite suppressants? The answer is
simply that plants species have had around 420 million years of evolution
in biochemical defences against herbivores. These evolutionary
defence mechanisms include around 100,000 different secondary metabolites,
many of which are anti-feedants for insects, birds and mammals
– in other words, chemicals to make those eating them feel full
and hopefully eat less. By examining these types of food components,
researchers hope to discover naturally active ingredients that act on
one or more of the multiple points within the GI tract that are known
to signal the brain to stop eating, including cholecystokinin (CCK) production
in the duodenum, the well-defined Ileal Brake mechanism and
colonic satiety mechanisms in the large intestine.
The aim of the research programme is to gain a greater understanding
of gut processes and develop enhanced appetite controls using
a “combinatorial” approach. To achieve this The Foods for Appetite
Control programme has brought together a world-leading and multidisciplinary
team (domestic and international) to approach both old
and new questions in novel ways.
In addition to the scientists at Plant & Food Research, the programme
also involves scientists from The University of Auckland and Massey
University, as well as collaborations with overseas experts involved
in understanding potential appetite control mechanisms triggered as
food passes along the digestive tract.
For more information please contact: Carl Massarotto, Business Support Manager, Plant & Food Research,
Carl.massarotto@plantandfood.co.nz
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Food New Zealand