High protein diets have led scientists to a new hunger suppressant that could help fight obesity.
Phenylalanine, a component of dietary protein, reduces food intake by affecting the release of appetite-regulating hormones in the gut, research has shown.
It may be the reason why diets that involve eating a lot of protein can be successful at promoting weight loss, experts believe.
However, high protein diets such as Atkins and Dukan can be hard to maintain and may result in long-term health problems, it is claimed.
The amino acid Phenylalanine is generated in the gut when protein is digested and has previously been shown to reduce appetite in rodents.
To investigate its effects, scientists at Imperial College London studied the brain activity and eating habits of mice treated with the chemical.
Rectal administration of phenylalanine was found to reduce food intake even at a dose 10 times lower than would be consumed daily as part of a high protein diet.
The amino acid also increased activation of an area of the brain known to be involved in regulating appetite.
Lead researcher Mariana Norton said: “Understanding how food is detected in the gut may help to identify ways of treating or preventing obesity. The next step is to establish whether phenylalanine can drive similar appetite-reducing effects in humans.”
She pointed out that while encouraging weight loss, high protein diets could be challenging.
Ms Norton added: “Identifying the mechanisms that sense the protein may allow us to use drugs or functional foods to hijack appetite regulation, and treat obesity.”
The findings were presented at the Society for Endocrinology’s annual meeting in Harrogate.