GETTYA handful of walnuts eaten every day could be the key to losing weight, according to new research
Researchers have found the humble nuts contain high amounts of a particular fat which prevent overeating.
Nuts are considered a superfood because they posses anti-inflammatory qualities and are also high in protein and fibre.
The latest research found walnuts are rich in polyunsaturated fats (PUFAS) which dampen down a hormone that boosts hunger, while firing up another that increases feelings of fullness.
Other foods rich in PUFAs include oily fish such as salmon and grapeseed oil.
PUFAs are known to be good for health by helping reduce cholesterol and providing essential fats like omega-6 and omega-3 that the body can’t produce itself.
The study, published in the journal Nutrition, involved 26 men and women aged 18 to 35 who had changes in hormone levels recorded as they were asked how hungry they felt.
The participants were placed on a seven day diet high in polyunsaturated fats. Then they consumed meals high in saturated fat again.
Both diets contained the same number of total calories and percentage of fat.
By monitoring the hormone levels, the scientists were able to see the PUFA diet was more likely to leave consumers feeling full.
It included whole foods such as walnuts, Alaska salmon, tuna, flaxseed oil, grapeseed oil and fish oil supplements.
Those that consumed a diet high in PUFAs had a significant decrease in fasting ghrelin, a hormone that increases hunger.
Meanwhile, there was a similar increase in peptide YY (PYY), a hormone that increases fullness or satiety.
GETTYThe humble nuts contain high amounts of a particular fat which prevent overeating
These types of hormone changes imply better appetite control.
Professor Jamie Cooper, a nutritionist at the University of Georgia in the US, said: “Appetite hormones play an important role in regulating how much we eat.
“These findings tell us that eating foods rich in PUFAs, like those found in walnuts, may favourably change appetite hormones so we can feel fuller for longer.”
Walnuts are unique among nuts because they are mainly comprised of PUFAs.
Every ounce - about seven whole walnuts - contains a remarkable 13 grams of PUFA out of 18 grams of total fat.
As a result they are the only nut to contain a significant amount of plant-based omega-3.
Prof. Cooper, whose study was funded by the California Walnut Commission, added that larger studies are now required.
More clinical trials are also needed to determine the optimal intake of dietary PUFAs to offer the greatest health benefit.
Walnuts have previously been linked with warding off cancer - and even dementia.
Regular snacking on them lowers cholesterol levels, improves heart health and can help diabetics stay healthy.
Just two ounces of the nuts can slash cholesterol levels by about a sixth.
Dietitian Jacqui Troughton said eating walnuts provided health benefits but warned against eating too many to prevent “unwanted weight gain”.