People who eat, walnuts, salmon and canola oil regularly are likely to experience favourable changes in appetite hormones associated with reduction in hunger.
The results suggested that study participants, who consumed a diet high in polyunsaturated fats (PUFAs) 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.
Lead researcher, Jamie A. Cooper, from the University of Georgia said that 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 that appetite hormones play an important role in regulating how much we eat.
They enrolled 26 healthy men and women (ages 18-35), who visited the lab for measurements and receive their meals throughout the study.
They asked the participants to eat diet high in PUFAs or a control diet consisting of a typical American eating pattern for seven days.
The PUFA-rich diet included whole foods such as walnuts, Alaska salmon, tuna, flaxseed oil, grapeseed oil, canola oil, and fish oil supplements.
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 percent poly-unsaturated fat, 15 percent mono-unsaturated fat and 13 percent saturated fat, compared to the PUFA-rich diet which was 21 percent poly-unsaturated fat, nine percent mono-unsaturated fat, and five percent saturated fat.
Walnuts are unique among nuts because they are primarily comprised of PUFAs, with 13 out of 18 grams of total fat per one ounce serving.
As a result, walnuts are the only nut to contain a significant amount of plant-based omega-3 alpha-linolenic acid (ALA) (2.5 grams per one ounce).
