According to Gram Research analysis, soybean oil showed only a weak, non-significant trend toward reducing liver fat compared to palm oil in a 16-week study of 65 adults with fatty liver disease. While soybean oil tended to decrease liver fat and palm oil tended to increase it, the differences disappeared when researchers adjusted for starting liver fat levels, suggesting that oil type alone may not be the key factor in treating fatty liver disease.
A new study compared how two different cooking oils affect people with fatty liver disease. Researchers gave 65 adults either soybean oil or palm oil for 16 weeks and measured changes in liver fat using special imaging. While soybean oil showed a slight tendency to reduce liver fat compared to palm oil, the differences weren’t strong enough to be definitive. The findings suggest that oil type alone may not be the key factor in treating fatty liver disease, and larger studies are needed to understand what dietary changes work best.
Key Statistics
A 16-week randomized controlled trial of 65 adults with metabolic-associated fatty liver disease found that soybean oil showed a non-significant trend toward reducing liver fat compared to palm oil, with differences no longer significant after adjusting for baseline liver fat levels.
In a 2026 double-masked study published in Diabetes, Obesity & Metabolism, consuming 30 grams daily of soybean oil versus palm oil produced no statistically significant difference in liver fat change when controlling for baseline liver fat in adults with fatty liver disease.
Research from a 16-week trial showed that weight change did not mediate the relationship between oil type and liver fat, suggesting that the effects of different oils on fatty liver disease are independent of body weight changes.
The Quick Take
- What they studied: Whether eating soybean oil (high in a type of fat called linoleic acid) versus palm oil affects the amount of fat stored in the liver of people with fatty liver disease.
- Who participated: 65 adults with an average age of 53 years who had been diagnosed with metabolic-associated fatty liver disease (MAFLD). Most were overweight, with an average BMI of 36.
- Key finding: Soybean oil showed a slight tendency to reduce liver fat while palm oil tended to increase it, but these differences were not statistically significant after accounting for starting liver fat levels. The study suggests oil type alone may not be the main factor affecting liver health.
- What it means for you: If you have fatty liver disease, simply switching to soybean oil may not be enough to improve your condition on its own. Weight management and overall dietary patterns likely matter more than the specific type of oil you use. Talk to your doctor about a comprehensive approach to treating fatty liver disease.
The Research Details
This was a double-masked randomized controlled trial, which is considered one of the strongest types of medical research. Participants were randomly assigned to eat either soybean oil or palm oil for 16 weeks, with neither the participants nor the researchers knowing which group was which (that’s what “double-masked” means). This design prevents bias from affecting the results.
Before the main study started, all participants went through a 2-week run-in period where they ate a standard diet. Then for 16 weeks, they consumed 30 grams (about 2 tablespoons) of their assigned oil daily through specially prepared study foods. At the beginning and end of the 16 weeks, researchers used advanced imaging technology called MRI to measure how much fat was in each person’s liver and belly area.
The study also collected blood samples to check for other health markers related to heart disease and metabolic problems. This comprehensive approach allowed researchers to see not just changes in liver fat, but also whether other health measures improved or worsened.
The randomized controlled trial design is important because it’s the gold standard for testing whether a specific treatment actually works. By randomly assigning people to groups and keeping both participants and researchers blinded to which oil they were getting, the study eliminates many sources of error. The use of precise MRI imaging to measure liver fat is also significant because it’s much more accurate than blood tests alone for detecting fatty liver disease.
This study has several strengths: it used a rigorous double-masked design, included precise imaging measurements, and was published in a respected peer-reviewed journal. However, the sample size of 65 people is relatively small for this type of research, which limits how confident we can be in the findings. The study lasted only 16 weeks, so we don’t know if effects would be different over longer periods. Additionally, the study didn’t control for overall diet quality or exercise, which could influence results.
What the Results Show
The main finding was that soybean oil and palm oil had different effects on liver fat, but the difference was not statistically significant when researchers adjusted for how much liver fat people had at the start of the study. In other words, the differences could have happened by chance.
When looking at each group separately, soybean oil showed a trend toward reducing liver fat (though this wasn’t statistically significant), while palm oil showed a trend toward increasing liver fat. However, these trends were weak and could easily be due to random variation rather than a true effect of the oils.
Interestingly, the researchers found that changes in body weight did not explain the differences between the two groups. This suggests that if there were any effects from the oils, they weren’t simply because people lost or gained weight. The study suggests that the type of fat in the oil may have some effect on liver health, but the effect is much smaller than researchers initially expected based on previous studies in healthy people.
The study measured several other health markers including visceral adipose tissue (the dangerous fat around organs), blood sugar control, cholesterol levels, and inflammation markers. However, the abstract doesn’t provide detailed results for these secondary outcomes. The researchers noted that larger studies are needed to properly evaluate whether different oils affect these other important health measures in people with fatty liver disease.
Previous research showed that soybean oil (which is high in linoleic acid) could reduce liver fat in healthy adults who weren’t trying to lose weight. This new study tested whether the same benefit would apply to people who already have fatty liver disease. The findings suggest that people with fatty liver disease may respond differently to dietary oils than healthy people do. This is an important distinction because it means we can’t simply assume that treatments that work for healthy people will work the same way for people with disease.
The study had several important limitations. First, 65 participants is a relatively small sample size, which means the results may not apply to larger populations. Second, the study only lasted 16 weeks, which is a short time frame for evaluating changes in liver disease. Third, the study didn’t control for other dietary factors or physical activity levels, which could significantly affect liver fat. Fourth, the study didn’t measure whether participants actually stuck to their assigned oil consumption. Finally, the study only included adults around age 53, so results may not apply to younger or older people with fatty liver disease.
The Bottom Line
Based on this research, switching to soybean oil alone is not recommended as a primary treatment for fatty liver disease. The evidence is weak and inconclusive. Instead, people with fatty liver disease should focus on comprehensive approaches including weight loss (if overweight), regular physical activity, and overall improvement in diet quality. These factors have stronger evidence for improving fatty liver disease. Consult with your healthcare provider or a registered dietitian for personalized recommendations.
This research is most relevant to adults with diagnosed metabolic-associated fatty liver disease (MAFLD) who are looking for dietary interventions. It’s also important for healthcare providers treating fatty liver disease. People without fatty liver disease should not assume these findings apply to them, as the study specifically tested people with existing liver disease. Those with other liver conditions should discuss this research with their doctor before making dietary changes.
This study only lasted 16 weeks, so we don’t know how long it would take to see meaningful changes in liver health from changing oils. Based on the weak trends observed, it’s unlikely that oil type alone would produce noticeable health improvements even over longer periods. Meaningful improvements in fatty liver disease typically require sustained lifestyle changes over months to years, including weight loss and increased physical activity.
Frequently Asked Questions
Is soybean oil better than palm oil for fatty liver disease?
A 16-week study of 65 adults with fatty liver disease found soybean oil showed only a weak, non-significant trend toward reducing liver fat compared to palm oil. The difference disappeared when adjusting for starting liver fat levels, suggesting oil type alone isn’t the key factor.
What should I eat if I have fatty liver disease?
This study suggests oil type alone won’t fix fatty liver disease. Focus on weight loss if overweight, regular exercise, and overall diet quality. Work with your doctor or dietitian for a comprehensive treatment plan tailored to your specific situation.
How long does it take to see improvements in fatty liver disease from diet changes?
This study only lasted 16 weeks and showed minimal changes. Meaningful improvements in fatty liver disease typically require sustained lifestyle changes over months to years, including weight loss and increased physical activity combined with overall dietary improvements.
Can I reverse fatty liver disease by changing my cooking oil?
Changing cooking oil alone is unlikely to reverse fatty liver disease based on this research. Reversing fatty liver disease typically requires a comprehensive approach including weight management, regular exercise, reduced sugar intake, and improved overall diet quality under medical supervision.
What type of fat is best for people with liver disease?
This study found no significant difference between soybean oil and palm oil for liver fat reduction. Rather than focusing on one oil type, people with liver disease should emphasize overall diet quality, portion control, and weight management as more important factors for liver health.
Want to Apply This Research?
- Track daily oil consumption (type and amount in grams) alongside weekly liver health markers if available through your healthcare provider. Log any changes in energy levels, digestion, or other symptoms that might correlate with dietary changes.
- If you have fatty liver disease, use the app to monitor your overall diet quality and weight trends rather than focusing solely on oil type. Set goals for increasing physical activity and reducing processed foods, which have stronger evidence for improving liver health than oil selection alone.
- Create a long-term tracking system that monitors weight, physical activity, overall diet quality, and any available liver function test results from your doctor. Review trends monthly rather than weekly, since liver fat changes typically occur slowly. Share this data with your healthcare provider to guide treatment decisions.
This research summary is for educational purposes only and should not be used as medical advice. Fatty liver disease is a serious condition that requires professional medical evaluation and treatment. Before making any dietary changes, especially if you have been diagnosed with metabolic-associated fatty liver disease (MAFLD) or any other liver condition, consult with your healthcare provider or a registered dietitian. This study involved a small sample size and lasted only 16 weeks, so results may not apply to all individuals or longer time periods. Individual responses to dietary interventions vary based on genetics, overall lifestyle, and other health factors.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.
