byUppsala University

The study evaluated a Nordic variant of the Mediterranean diet, which was found to contribute to weight loss as well as reduced levels of liver fat. This salmon salad is an example of a dish that fits within a healthy Nordic diet. It was developed by the research group. Credit: Andréa Flores

A healthy Nordic diet, high in dietary fiber from whole grains, fruits and vegetables but with a small percentage of saturated fat, can assist in the treatment of both type 2 diabetes and non-alcoholic fatty liver disease. This has been shown in a new clinical study in which the researchers compared three different types of diet.

After one year, researchers at Uppsala University have been able to show in this new study that a 'healthy Nordic diet' is better than both the Nordic Nutrition Recommendations and a low-carbohydrate diet when it comes to treating non-alcoholic fatty liver disease and type 2 diabetes.

"The healthy Nordic diet gave the best results in the study participants with diabetes; just over 20% of their liver fat was reduced and blood sugar (glucose) control improved over one year. More than half of the participants also saw a remission of their fatty liver disease. This makes these results equally important for people with non-alcoholic fatty liver disease as those with type 2 diabetes," says Ulf Risérus, Professor of Clinical Nutrition and Metabolism, who led the study.

The paper ispublishedin the journalNature Communications.

The study was a randomized controlled trial in which 150 people with type 2 diabetes, or prediabetes, were randomly assigned to follow one of three diets for one year:

In all three groups, participants were to limit their consumption of red and processed meats, sweetened drinks, sweets and candy, and snacks with added sugar.

All three diets were expected to have beneficial effects, but the researchers wanted to investigate which was the most effective in reducing both liver fat and blood glucose levels. That the Nordic diet turned out to be so good surprised the researchers, who had assumed that the anti-lipogenic diet would yield the best results.

"The study shows that both the anti-lipogenic diet and the Nordic diet were relatively similar in reducing liver fat as well as 'bad' LDL cholesterol. But the healthy Nordic diet was more effective in reducing blood glucose over the long term, and also had more beneficial effects on body weight, inflammation and lipid profile, as well as reducing signs of liver damage," Risérus explains.

The study also shows that the diets were surprisingly easy to follow.

"Even though the participants were allowed to eat as much as they wanted from the foods recommended, they still lost weight. In many previous studies of different diets, calorie intake has been restricted, which is effective in the short term, but increases hunger and can be difficult to follow in the longer term," says Michael Fridén, the lead author of the study.

Although some of the beneficial effects of thehealthy Nordic dietcould be explained by the participants' weight loss, the researchers found that weight loss only explained just over half (56%) of the effect on liver fat.

"This is very interesting, as it suggests that the diet itself has contributed to reducing fat deposits in the liver, but probably also to improved blood glucose levels and lipid values as well as reducing inflammation. There has been a great need to find new, evidence-based diets for long-term diabetes care. Our results are important for future dietary recommendations and are particularly important for overweight people with Type 2 diabetes or prediabetes," says Risérus.

More information Michael Fridén et al, Effects of an anti-lipogenic low-carbohydrate high polyunsaturated fat diet or a healthy Nordic diet versus usual care on liver fat and cardiometabolic disorders in type 2 diabetes or prediabetes: a randomized controlled trial (NAFLDiet), Nature Communications (2025). DOI: 10.1038/s41467-025-65613-2 Journal information: Nature Communications

Provided by Uppsala University