Eating more protein can help increase levels
of a hunger-fighting hormone called peptide
YY (PYY), British scientists report.
Previous research found that injections of
PYY could reduce food intake by a third in
both normal-weight and obese people.
"We've now found that increasing the
protein content of the diet augments the body's
own PYY, helping to reduce hunger and aid
weight loss," study leader Rachel Batterham,
of University College London, said in a prepared
statement.
In research with obese and normal-weight
people, Batterham and her colleagues found
that boosting the amount of protein in the
diet stimulated greater release of PYY in
the body than either high-fat or high-carbohydrate
meals, resulting in a greater reduction of
hunger.
Further investigation in mice found that
high-protein diets increased the rodents'
PYY levels and reduced the number of calories
they consumed. Mice fed a high-protein diet
also produced more PYY and gained less weight
than mice fed the usual amount of protein.
Batterham's team also found that genetically
modified mice unable to produce PYY ate more
and became extremely obese. These mice were
resistant to the effects of a high-protein
diet, which demonstrates a direct link between
protein and PYY, the scientists concluded.
When the genetically modified mice were treated
with PYY, they lost weight.
"The findings show that PYY deficiency
can cause obesity and that PYY appears to
mediate the beneficial effects of increased
protein-content diets," Batterham said.
"One potential weight-loss strategy is
therefore to increase the satiating power
of the diet and promote weight loss through
the addition of dietary protein -- harnessing
our own satiety system."
She said much more research is needed before
any particular high-protein diet could be
recommended. Batterham emphasized that any
such diet would not resemble the Atkins diet,
which is high in both saturated fat and protein.
The findings were published in the September
issue of Cell Metabolism.
