Eating walnuts may help control appetite: study

Millennials who regularly consume foods rich in polyunsaturated fats, such as walnuts and salmon, are likely to experience hormonal changes that control appetite and make them feel full, a study has found.
Specific hormones in the body help control appetite. Some hormones are responsible for signalling the body to eat, whereas others tell the body it is full, or satiated.
Researchers from University of Georgia in the US looked at physiological hunger and satiety responses by measuring hormone changes, as well as subjective ratings by asking participants to indicate on a scale how hungry or full they were and how much they thought they could eat.

They found that participants that consumed a diet high in polyunsaturated fats (PUFA) had a significant decrease in fasting ghrelin, a hormone that increases hunger, and a significant increase in peptide YY (PYY), a hormone that increases fullness or satiety.
Participants saw increases in PYY while fasting and after consuming a meal. These types of hormone changes imply better appetite control, researchers said.
There were no changes in the subjective ratings in either the PUFA-rich diet or the control diet.

Appetite hormones play an important role in regulating how much we eat, researchers said.
"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," said Jamie A Cooper, PhD student at University of Georgia.

Researchers enrolled 26 healthy men and women between the ages of 18 and 35 (millennials) who visited the lab for measurements and to receive their meals throughout the study.
At the beginning of the study, participants were measured and they consumed test meals high in saturated fat.
Researchers then placed subjects 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.
After the seven-day diet, participants consumed test meals high in saturated fat, again. The two diets contained the same number of total calories and percent of calories from fat but differed in the types of fat included.

The control diet was comprised of seven 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, nine per cent monounsaturated fat, and five per cent saturated fat.
The study was published in the journal Nutrition.