Individuals who regularly consume walnuts, salmon and canola oil -- rich in polyunsaturated fats (PUFAs) -- are likely to experience hormonal changes that can control appetite and make them feel less hungry, a study has shown.

The study found that consuming a diet high in PUFAs caused a significant decrease in fasting ghrelin -- a hormone that increases hunger.Further, a PUFA rich diet also caused significant increase in peptide YY (PYY) -- a hormone that increases fullness or satiety. "Appetite hormones play an important role in regulating how much we eat," said lead researcher Jamie A. Cooper, from the University of Georgia."These findings tell us that eating foods rich in PUFAs, like those found in walnuts, may favourably change appetite hormones so that we can feel fuller for longer," Cooper added.For the study, detailed in the journal Nutrition, the team enrolled 26 healthy men and women (ages 18-35) who were placed on a seven-day diet high in PUFAs or a control diet consisting of a typical American eating pattern. 

The PUFA-rich diet included whole foods such as walnuts, Alaska salmon, tuna, flaxseed oil, grape-seed oil, canola oil, and fish oil supplements. All meals were provided by the researchers. The control diet was comprised of 7 per cent polyunsaturated fat, 15 per cent monounsaturated fat and 13 per cent saturated fat, compared to the PUFA-rich diet which was 21 per cent polyunsaturated fat, 9 per cent monounsaturated fat, and 5 per cent saturated fat.The participants experienced increases in PYY while fasting and after consuming a meal. These types of hormone changes imply better appetite control, the researchers said.