America’s Most Popular Cooking Oil Linked to Obesity in New StudyDec 01, 2025 at 10:18 AM EST By Jasmine Laws, US News Reporter A new study has found that soybean oil contributed to obesity in mice, prompting concern that the United States' most popular cooking oil could be playing a role in the country's obesity problem. The University of California, Riverside study, published in the Journal of Lipid Research in October, investigated how mice metabolized linoleic acid, an omega-6 fatty acid widely present in soybean oil, by feeding them a high-fat diet based on the common cooking oil. While the study was conducted on mice, Frances Sladek, a UCR professor of cell biology and author of the study, told Newsweek that the findings "were translatable to humans as the pathways we found involved in soybean oil-induced obesity are highly conserved between mouse and human." Why It MattersSoybean oil is by far the most widely used cooking oil in the country, with rapeseed oil second and palm oil third, according to data from Statista. Soybean oil is also made up of more than 50 percent linoleic acid, Sladek said. The finding raises notable concern, not only because of the oil's popularity, but also because of America's high obesity rates—one in five children and two in five adults are obese in the U.S., meaning they have a Body Mass Index (BMI) higher than 30. Obesity is known to be associated with higher risks of health problems, including diabetes, heart disease and strokes. The American diet has also been called into question by studies previously, as last year a study found that the majority of Americans ate a diet that promoted inflammation, increasing the risk of diseases such as heart disease, obesity, diabetes, depression and certain cancers. Stock image: A person pours soybean oil into a frying pan. | coffeekai/Getty Images What To KnowThe study specifically examined the effects of molecules called oxylipins on mice. These molecules are what linoleic acid is broken down into in the body, and so the higher the consumption of the acid, the higher the amount of these molecules will be in the body. While other fatty acids also break down into oxylipins, the oxylipins derived from linoleic acid were the ones the authors found contributed to obesity in mice. The finding is not new; the researchers noted this result in a previous study. What they did differently in this study was test the impact of a diet high in soybean oil in a group of male mice genetically engineered to express a different version of a liver regulatory gene, P2-HNF4α. This meant they had different metabolic pathways from the control group, as the genetic change reduced the activity of enzymes that convert linoleic acid into oxylipins. The researchers found that the modified mice had healthier livers and gained less weight than the control group on the same diet, further supporting the idea that oxylipins contribute to obesity. “This may be the first step toward understanding why some people gain weight more easily than others on a diet high in soybean oil,” said Sonia Deol, a UCR biomedical scientist and another author of the study. Although the researchers also note that the genetically modified mice had elevated oxylipins on a low-fat diet without becoming obese, suggesting that other metabolic factors are at play. Sladek said that they found that "it is the levels of the oxylipins present in the liver, not circulating in the blood, that correlate with obesity." However, he said that they aren't yet certain about "exactly how the oxylipins drive obesity." How Much Soybean Oil Do Americans Actually Consume?Consuming a small amount of linoleic acid is actually required for human health and is part of a healthy diet; however, the researchers noted that America has had a "remarkable increase" in its consumption of the oil over the past 50 years. The required amount of linoleic acid for health is around 1 to 2 percent of a person's calorific intake, the study authors noted, as small amounts play an important role in maintaining good health. Most Americans broadly have a much higher intake of linoleic acid at around 15 to 25 percent of their calorific intake, the study authors said. Sladek said that consuming small amounts of soybean oil is "perfectly safe and provides a good source of the essential fatty acid linoleic acid." He said that the problem is that "processed foods are becoming an ever larger part of our diet and many of those foods have soybean oil in them, or they have corn oil, safflower seed oil, sunflower seed oil — all these seed oils are made up of large amounts of linoleic acid, just like soybean oil." "So in general, we are taking in much more of these seed oils, all of which have high levels of linoleic acid, than our body needs," he added. What Does Soybean Oil Do to Your Body?It is not clear from the study how these findings would translate to the human body, and further research is needed to determine the impact of soybean oil on human health. However, the study authors note that the findings suggest the possible link warrants further investigation. Sladek said: "It took 100 years from the first observed link between chewing tobacco and cancer to get warning labels on cigarettes. We hope it won’t take that long for society to recognize the link between excessive soybean oil consumption and negative health effects." He also told Newsweek that in previous research, the team found that the soybean oil could impact the intestines, the microbiome and the hypothalamus. He said that while there is a growing body of evidence indicating that dietary linoleic acid is beneficial for the heart, "we have not looked at the impact of a soybean oil diet on the heart." "Different organs will respond differently to dietary linoleic acid and more research in general needs to be done," Sladek added. Other experts are not convinced of the findings, though. Dr. Dariush Mozaffarian, the director of the Food is Medicine Institute at Tufts University, told Newsweek: "Much of the original research suggesting harms of omega-6 [polyunsaturated fatty acids], like this study, was done in mice or rats." "We’ve since clearly learned that humans are not mice, and that these effects don’t translate to what’s seen in humans," Mozaffarian said. "In mice, for example, high fat diets (from any source) cause obesity, whereas in humans, carbs are the problem." He said that in controlled trials in humans, soybean oil and omega-6 polyunsaturated fatty acids were found to "improve blood cholesterol levels, improve glucose control, and lower risk of heart attacks," while in "observational studies," these oils are "linked to less weight gain and obesity risk." Mozaffarian said that soybean oil is a "healthy oil for cooking," and pointed to studies finding that a tablespoon and a half daily of soybean oil could reduce the risk of coronary heart disease, that the oil does not have pro-inflammatory effects, and that those who consumed 5 grams a day had a lower risk of "all-cause mortality." ARTICLE SOURCE: https://www.newsweek.com/soybean-oil-linked-to-obesity-study-11133940
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comment_11183When Ozempic didn't work, I went on a diet doctors warn against... the results speak for themselves
By LUKE ANDREWS SENIOR HEALTH REPORTER FOR DAILYMAIL.COM
Published: 12:15 EDT, 22 April 2025 | Updated: 14:30 EDT, 22 April 2025
At 635lb and struggling to walk, Pete Brennan knew something needed to change.
Showing people houses for his realtor job left him panting and with shooting pains through his knees and feet that would last hours.
His wife had to assume all cooking and cleaning duties at home, leaving him feeling useless and worthless.
Brennan, 39, nearly missed his own wedding, narrowly avoiding being ordered off the plane to Mexico because he was too large to fit into the single passenger seat.
But the breaking point came when Brennan fell in the shower and was unable to stand up, having to ask his five-year-old son Nolan to help him.
'It just kind of made me realize that being selfish, and letting go of myself like I was, that really wasn't the right thing to do,' Brennan told the Daily Mail.
The New Jersey native has now successfully shed more than half his body weight, or 352lbs, in two years while following a diet almost all doctors advise against.
The 'carnivore diet' involves eating only meat products like steak, chicken, eggs, butter and fish.
Brennan is pictured above around his heaviest at 635lbs with two clients. He works as a realtor helping to sell houses
Peter 'Francis' Brennan, 39, has embarked on a mammoth weight loss to slash his weight from 635 to below 250lbs. He is currently at 283lbs, and is pictured above this month
The high levels of fats and low carbohydrates puts the body into ketosis, a state where it burns bodyfat instead of carbohydrates for energy.
Many doctors, including Brennan's, warn people not to use the diet saying that it can cause high levels of LDL or bad cholesterol.
This can cause plaques to build-up in the arteries, restricting blood flow and raising the risk of complications like high blood pressure, heart disease, stroke and a heart attack — which he was already at risk of.
Some, however, say it's a life changer, including podcaster Joe Rogan and controversial psychologist Jordan Peterson.
Advocates say the carnivore diet allows them to lose weight rapidly and boost their energy levels, sleep and sexual performance.
Brennan said he now consumes three meals a day, with each weighing six ounces and composed entirely of eggs mixed with sliced chicken and turkey sausages.
He aims to get in about 130 to 170 grams of protein daily, well above the US National Dietary Guidelines recommendation of about 0.36 grams of protein per pound of body weight — or 101 grams a day for Brennan, who weighs 283lbs.
For snacks, he consumes peanuts and cottage cheese — which aren't strictly part of the carnivore diet but are used in the keto diet to keep burning fat for energy.
He doesn't consume red meat amid concerns that it could cause colon cancer and type 2 diabetes.
Brennan shown in the gym this month
Brennan started on the carnivore diet in June 2024, after spending a year and four months on Wegovy — injecting himself once a week.
He also had gastric sleeve surgery in June 2024, when the stomach is surgically reduced to limit the amount of food someone can consume.
Surgeons were shocked operating on him, saying at the time that his stomach was three foot long — or about three times the average size for a person.
The drugs caused him to lose 167lbs in a year and four months, which he used alongside a restrictive diet and exercise six times a week.
But the diet and surgery is what really yielded the results, leading him to lose an extra 185lbs the following nine months.
His current weight is now 283lbs, which at 5ft 11in still puts him in the obese category with a BMI above 30. When he started his weight loss, his BMI was 88 — putting him in the category of severely obese.
He aims to get his weight below 250lbs before December — and then reach his goal of weighing between 200 and 225lbs.
But despite the enormous success he has had, Brennan confessed he isn't feeling nearly as confident as he should — and its all down to the massive amount of loose skin hanging off his body.
When someone puts on a large amount of weight, the skin stretches to accommodate the new size. It may then struggle to return to its original size if someone later loses the weight.
In Brennan's case, his loose skin is 'everywhere' — hanging off his chest, stomach, back, legs, arms, neck and his face. It isn't clear how much it weighs.
Peter is pictured above at the start of his weight loss journey. He has been posting his workouts online
'I don't feel as confident as I should be after doing what I've done,' he said, 'just because I know it is just hanging there'.
'It's not how a normal person should look, I look like I've melted.
'Like, if it wasn't there I would be wearing smaller size clothes, and my legs wouldn't be as hidden.'
As well as getting in the way, the skin can also chafe against itself and clothing — causing him to develop painful rashes that take days to clear up.
His health insurance covered the Wegovy and gastric sleeve surgery, but has declined to cover the skin removal, saying this is cosmetic.
With the mammoth procedure needed, doctors have estimated it will cost $90,000 — which he is fundraising for online. He says he is also considering taking out a loan to cover the rest.
He also had surgery to remove a hernia at his belly button, with a hernia being when part of the intestine, fat or fluid pushes through a weak spot in the abdominal wall and creates a visible bulge.
Hernias may happen because of increased pressure in the abdomen, which may be caused by straining during bowel movements or obesity.
He had had the hernia for ten to 15 years, but it had not previously been possible to treat it owing to his weight.
Pete Brennan, 39, New Jersey, is pictured above at the start of his weight loss journey at 635lbs and today after getting his weight down to 283lbs. The structure in the middle of his stomach is a hernia, which he has now had removed
Brennan is thrilled with his weight loss, but said his confidence has been hit by his loose skin
Amid all the weight loss, Brennan said his life is transformed — with himself now able to help around the house and having a lot more energy.
He also works out six times a week, focusing on a combination of cardio and weight-lifting, and said people no longer stare at him in the street, like they did when he was much larger.
A number of people viewing his photos have said they don't want to lose weight because of the loose skin, but Brennan urged them to reconsider.
He said: 'I would say you just need to put the excuse aside and think more long term about how beneficial it is going to be on your life and how much longer you are going to be able to live.
'And guess what, you can get rid of loose skin with surgery...'
He added: 'Once you're past making excuses and are actually doing it, you will start to love it and start to love the new self you are turning into.'
ARTICLE SOURCE: https://www.dailymail.co.uk/health/article-14511377/ozempic-failure-diet-carnivore-weight-loss.html?
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