Diets rich in polyunsaturated fats may alter appetite hormones among millennials

June 15, 2017
New published research shows millennials (ages 18-35) who regularly consume foods that contain polyunsaturated fats (PUFAs), such as walnuts, salmon and canola oil, may experience favorable changes in appetite hormones associated with hunger and satiety. Credit: California Walnut Commission

New published research shows millennials (ages 18-35) who regularly consume foods that contain polyunsaturated fats (PUFAs), such as walnuts, salmon and canola oil, may experience favorable changes in appetite hormones associated with hunger and satiety. Specific hormones in the body help control appetite. Some hormones are responsible for signaling the body to eat, whereas others tell the body it's full, or satiated. Research is exploring how foods may reduce hunger or increase satiety by influencing these hormones. These types of hormonal changes could ultimately play a role in achieving optimal body weight.

In this study, researchers looked at physiological hunger and satiety responses by measuring 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. Study participants that consumed a diet high in 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. Participants saw increases in PYY while fasting and after consuming a meal. These types of imply better appetite control. 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," said lead researcher, Jamie A. Cooper, PhD of the University of Georgia. "These findings tell us that eating foods rich in PUFAs, like those found in walnuts, may favorably change so that we can feel fuller for longer."

Researchers enrolled 26 healthy men and women (ages 18-35) 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, grapeseed oil, , and . 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 was comprised of 7% polyunsaturated fat, 15% monounsaturated fat and 13% saturated fat, compared to the PUFA-rich diet which was 21% polyunsaturated fat, 9% monounsaturated fat, and 5% 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). Research on the health benefits of PUFAs continues to evolve and most recently the 2015-2020 Dietary Guidelines for Americans has recommended consuming this type of fat in place of saturated fat.

As with any research study, it is important to consider the limitations. Larger and longer-term studies, as well as studies in diverse populations, are needed to clarify population-wide effects. In the context of a whole food diet, such as the diet used in this study, it is difficult to discern whether changes seen with the PUFA-rich diet can be attributed to one specific type of PUFA, food source, or a combination of overall dietary factors. More clinical trials are needed to determine the optimal intake of dietary PUFAs to offer the greatest health benefit.

Explore further: Eating diet high in polyunsaturated fats can protect against effects of 'splurge' meals, study finds

More information: Jada L. Stevenson et al, Hunger and satiety responses to high-fat meals after a high-polyunsaturated fat diet: A randomized trial, Nutrition (2017). DOI: 10.1016/j.nut.2017.03.008

Related Stories

Eating diet high in polyunsaturated fats can protect against effects of 'splurge' meals, study finds

June 2, 2016
A diet that includes higher amounts of polyunsaturated fats, found in foods like walnuts and salmon, can help offset the detrimental effects of the occasional meal high in saturated fats, University of Georgia researchers ...

Walnuts may support sperm health, according to new animal research

February 28, 2017
New animal research suggests eating a walnut-enriched diet may improve sperm quality by reducing lipid peroxidation, a process that can damage sperm cells. This form of cell damage harms sperm membranes, which are primarily ...

Researchers connect common fats to a lazy lifestyle and diabetes

April 12, 2017
A UBC researcher is suggesting the types of cooking oils people consume may be sabotaging their efforts to stay healthy and avoid illnesses such as diabetes.

Children who are leaner report eating more polyunsaturated fatty acids

August 12, 2015
The results of a recent study show that children who report eating more polyunsaturated fatty acids (PUFAs), found in tree nuts, seeds and fatty fish, and consume a higher ratio of PUFA: saturated fatty acids (SFAs), have ...

A pack of walnuts a day keeps the fertility specialist away?

August 15, 2012
A paper published 15 August 2012 in Biology of Reproduction's Papers-in-Press reveals that eating 75 grams of walnuts a day improves the vitality, motility, and morphology of sperm in healthy men aged 21 to 35.

Study examines dietary fatty acid intake, risk for Lou Gehrig disease

July 14, 2014
Eating foods high in ω-3 polyunsaturated fatty acids (PUFAs) from vegetable and marine sources may help reduce the risk for amyotrophic lateral sclerosis (ALS), the fatal neurodegenerative disease commonly referred to as ...

Recommended for you

Study links health risks to electromagnetic field exposure

December 13, 2017
A study of real-world exposure to non-ionizing radiation from magnetic fields in pregnant women found a significantly higher rate of miscarriage, providing new evidence regarding their potential health risks. The Kaiser Permanente ...

Increased air pollution linked to bad teenage behavior

December 13, 2017
A new study linking higher levels of air pollution to increased teenage delinquency is a reminder of the importance of clean air and the need for more foliage in urban spaces, a Keck School of Medicine of USC researcher said.

175 years on, study finds where you live still determines your life expectancy

December 13, 2017
Research led by the University of Liverpool has revisited a study carried out 175 years ago which compared the health and life expectancy of people in different parts of the country, including Liverpool, to see if its findings ...

Postmenopausal women should still steer clear of HRT: task force

December 12, 2017
(HealthDay)—Yet again, the nation's leading authority on preventive medicine says postmenopausal women should avoid hormone replacement therapy (HRT).

Will 'AI' be part of your health-care team?

December 12, 2017
(HealthDay)—Artificial intelligence is assuming a greater role in many walks of life, with research suggesting it may even help doctors diagnose disease.

State-level disclosure laws affect patients' eagerness to have their DNA tested

December 12, 2017
Different types of privacy laws in U.S. states produce markedly different effects on the willingness of patients to have genetic testing done, according to a new study co-authored by an MIT professor.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.