Minder honger door meer proteines.*
Uit een studie blijkt dat het eten van meer proteïnes (eiwitten) het hongergevoel doet afnemen. Uit eerder studies was al gebleken dat voeding met meer proteïnes aanzet tot minder eten en daardoor een beter lichaamsgewicht, maar het hoe en waarom waren nog onduidelijk. Wel was bekend dat een bepaald hormoon (PYY) zorgt voor de mindere honger. Injecties met deze hormonen in een eerdere studie deed de hoeveelheid ingenomen voedsel bij zowel normale als zwaarlijvige mensen met een derde afnemen. In deze studie is nu gebleken dat voeding rijk aan proteïnes de aanmaak van PYY in het lichaam ook doet toenemen en daardoor neemt het hongergevoel ook duidelijk af.
Stave
Off Hunger With Protein
The
amount of a hunger-fighting hormone can be increased by eating a higher protein
diet, researchers report in the September issue of the journal Cell Metabolism,
published by Cell Press. The hormone, known as peptide YY (PYY), was earlier
found by the researchers to reduce food intake by a third in both normal-weight
and obese people when given by injection.
"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," said
Medical Research Council clinician scientist Rachel Batterham of University
College London, who led the new study.
Scientists have known that high-protein content meals make people feel more full
and reduce food intake, resulting in improvements in weight loss and weight loss
maintenance. However, the mechanism responsible remained elusive.
In a study in normal-weight and obese people, the researchers now show that
enhanced-protein meals stimulate greater release of PYY than either high-fat or
high-carbohydrate meals and result in a greater reduction of hunger.
Further investigation in mice supported the human study results. High-protein
diets reduced the number of calories animals consumed and increased their PYY
levels. Mice fed a high-protein diet also gained less weight and produced more
PYY than animals that ate the usual amount of protein, they found.
In addition, the researchers found that genetically modified mice unable to
produce PYY ate more and became markedly obese. The genetically modified mice
were also resistant to the beneficial effects of a high-protein diet, the
researchers reported, demonstrating a direct connection between protein and PYY.
When the researchers treated those hormone-deficient mice with PYY, the animals
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.
"Such a diet is perhaps more typical to that of our hunter-gatherer
ancestors," she added.
The average Western diet derives 49% of energy intake from carbohydrate, 35%
from fat, and 16% from protein, Batterham said. That differs considerably from
the diet of hunter-gatherers, who ate as much as twice the amount of protein.
Batterham cautioned, however, that large, long-term clinical trials are required
before any particular diet could be recommended. She also noted that such a diet
would not resemble the popular Atkins diet, which is typically high in both
saturated fat and protein.
###
The researchers include Rachel L. Batterham, Helen Heffron, Saloni Kapoor,
Joanna E. Chivers, Keval Chandarana, and Dominic J. Withers of the University
College London in London, UK; Carel W. Le Roux of Hammersmith Hospital, Imperial
College in London, UK; . Louise Thomas and Jimmy D. Bell of Imperial College
London, Hammersmith Hospital Campus in London, UK; Herbert Herzog of The Garvan
Institute of Medical Research, St. Vincent's Hospital in Sydney, Australia.
This work was supported by grants from the Medical Research Council (R.L.B.,
D.J.W., J.E.C., and J.D.B.), Wellcome Trust (D.J.W.), UCLH Charities CDRC
(R.L.B.), and Travers Legacy (R.L.B.) and grant no. 188 827 from the National
Health and Medical Research Council of Australia (H.H.). R.L.B. is an MRC
Clinician Scientist.
Batterham et al.: "Critical role for peptide YY in protein-mediated
satiation and body-weight regulation." Publishing in Cell Metabolism 4,
223-233, September 2006. DOI 10.1016/j.cmet.2006.08.001
(Sept.
2006) (Opm. Kijk bij Voedingstoffen
over informatie over eiwitten)