By Tia Ghose, Staff Writer
Published: 03/04/2014 02:59 PM EST on LiveScience
The type of fat you eat may affect not only your heart disease risk, but also where on your body you pack on extra pounds, new research suggests.
People who ate extra amounts of saturated fat tended to accumulate fat around their waistlines and livers. Meanwhile, people who consumed extra amounts of polyunsaturated fat, which typically comes from vegetable oils, had trimmer waistlines, a new study found.
Fat around the waistline, or "belly" fat, and fat near the liver are thought to be particularly unhealthy, and have been linked to increased risk of diabetes and heart disease.
The new findings reinforce current dietary guidelines, which say people should eat more polyunsaturated fats from vegetable oil and fatty fish, and fewer saturated fats from red meat and butter, said study co-author Ulf Riserus, a clinical nutrition professor at Uppsala University in Sweden.
Research has tied carrying extra pounds around the mid-section to metabolic syndrome, a collection of symptoms linked to heart disease and diabetes. Those symptoms include high blood pressure, low HDL or "good" cholesterol, and high blood sugar.
It's unclear exactly why belly fat affects health risks to such an extent, but one theory suggests that liver and belly fat may be more responsive to stress hormones, causing the release of more fatty acids into the liver. That, in turn, may make it more difficult for the liver to respond to insulin, the hormone that regulates blood sugar, Riserus said.
Many studies have linked diets high in saturated fats with higher heart-disease risk, but the reason for this link wasn't clear. [7 Foods Your Heart Will Hate]
To understand more about the link between saturated fats and heart disease, Riserus and his colleagues gave 39 young men and women a 750-calorie muffin every day, to eat in addition to their normal diets. Half of the muffins were made with palm oil, a saturated fat, whereas the rest were baked with sunflower oil, a polyunsaturated fat.
After seven weeks, the researchers measured the fat that the participants had accumulated during the study, as well as their total body fat. Researchers made these measurements using magnetic resonance imaging (MRI) and an air-displacement plethysmograph, which registers a person's overall density and volume.
Both groups of subjects put on roughly the same number of pounds, but those who ate the saturated fat-filled treats tended to accumulate that weight around the stomach and visceral organs, according to the study. These individuals also put on much less muscle mass than those who ate the unsaturated fat muffins.
Different gene expression
The team also measured gene expression in abdominal subcutaneous fat, which is fat located just under the skin.
"We found that polyunsaturated fats 'switched on' some genes that enhance energy dissipation, limit body fat deposition and may promote muscle mass gain," Riserus told Live Science.
It's not clear why unsaturated fats may promote a healthier accumulation of fat, but the study hints that fat in different parts of the body may activate different genes that may favor one type of fat deposition over another, Riserus said.
Some early evidence suggests the foods themselves could affect how the body processes nutrients, said study co-author Fredrik Rosqvist, a doctoral candidate in public health and caring sciences at Uppsala University.
So it's possible that the body could process saturated fats differently when they're consumed in a muffin versus a plate of bacon, Rosqvist said.
The findings were published online Feb. 18 in the journal Diabetes.
Follow Tia Ghose on Twitter and Google+. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.
Copyright 2014 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed. ]]>
Our 2024 Coverage Needs You
It's Another Trump-Biden Showdown — And We Need Your Help
The Future Of Democracy Is At Stake
Our 2024 Coverage Needs You
Your Loyalty Means The World To Us
As Americans head to the polls in 2024, the very future of our country is at stake. At HuffPost, we believe that a free press is critical to creating well-informed voters. That's why our journalism is free for everyone, even though other newsrooms retreat behind expensive paywalls.
Our journalists will continue to cover the twists and turns during this historic presidential election. With your help, we'll bring you hard-hitting investigations, well-researched analysis and timely takes you can't find elsewhere. Reporting in this current political climate is a responsibility we do not take lightly, and we thank you for your support.
Contribute as little as $2 to keep our news free for all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
The 2024 election is heating up, and women's rights, health care, voting rights, and the very future of democracy are all at stake. Donald Trump will face Joe Biden in the most consequential vote of our time. And HuffPost will be there, covering every twist and turn. America's future hangs in the balance. Would you consider contributing to support our journalism and keep it free for all during this critical season?
HuffPost believes news should be accessible to everyone, regardless of their ability to pay for it. We rely on readers like you to help fund our work. Any contribution you can make — even as little as $2 — goes directly toward supporting the impactful journalism that we will continue to produce this year. Thank you for being part of our story.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
It's official: Donald Trump will face Joe Biden this fall in the presidential election. As we face the most consequential presidential election of our time, HuffPost is committed to bringing you up-to-date, accurate news about the 2024 race. While other outlets have retreated behind paywalls, you can trust our news will stay free.
But we can't do it without your help. Reader funding is one of the key ways we support our newsroom. Would you consider making a donation to help fund our news during this critical time? Your contributions are vital to supporting a free press.
Contribute as little as $2 to keep our journalism free and accessible to all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
As Americans head to the polls in 2024, the very future of our country is at stake. At HuffPost, we believe that a free press is critical to creating well-informed voters. That's why our journalism is free for everyone, even though other newsrooms retreat behind expensive paywalls.
Our journalists will continue to cover the twists and turns during this historic presidential election. With your help, we'll bring you hard-hitting investigations, well-researched analysis and timely takes you can't find elsewhere. Reporting in this current political climate is a responsibility we do not take lightly, and we thank you for your support.
Contribute as little as $2 to keep our news free for all.
Can't afford to donate? Support HuffPost by creating a free account and log in while you read.
Dear HuffPost Reader
Thank you for your past contribution to HuffPost. We are sincerely grateful for readers like you who help us ensure that we can keep our journalism free for everyone.
The stakes are high this year, and our 2024 coverage could use continued support. Would you consider becoming a regular HuffPost contributor?
Dear HuffPost Reader
Thank you for your past contribution to HuffPost. We are sincerely grateful for readers like you who help us ensure that we can keep our journalism free for everyone.
The stakes are high this year, and our 2024 coverage could use continued support. If circumstances have changed since you last contributed, we hope you'll consider contributing to HuffPost once more.
Support HuffPostAlready contributed? Log in to hide these messages.