Most of us judge weight loss by what happens on the scales, how our clothes fit or whether the waistline has become a little more forgiving. What those measurements cannot tell us is how much fat may be accumulating inside our organs.
That distinction matters, particularly when it comes to the pancreas.
Researchers have found that a modified Mediterranean diet, rich in plant compounds known as polyphenols, was associated with a 14% relative reduction in pancreatic fat over 18 months. The findings suggest that where the body stores fat, and how those deposits respond to dietary changes, could be important for understanding metabolic health.
The research, led by Ben-Gurion University of the Negev and published in The American Journal of Clinical Nutrition, forms part of the international DIRECT-PLUS clinical trial.
Its significance goes beyond weight loss. Researchers also found associations between reductions in pancreatic fat and improvements in measures of insulin resistance, even after accounting for changes in abdominal fat.
Why Fat Inside the Pancreas Matters
The pancreas performs an essential job in regulating blood sugar. Among its functions is producing insulin, the hormone that helps glucose move from the bloodstream into the body’s cells.
Problems can develop when fat accumulates in and around the organ.
Known as ectopic fat, these deposits occur in tissues that are not primarily designed to store fat. Elevated pancreatic fat has been associated with insulin resistance, poorer blood-sugar regulation and an increased risk of type 2 diabetes.
Researchers are interested in whether this fat contributes to metabolic problems directly, rather than simply accompanying excess bodyweight.
It is a distinction that reflects a broader issue with conventional weight measurements. As our earlier examination of why BMI cannot tell the whole story about body fat explains, where fat accumulates can be as important as how much a person carries.
Unlike some other metabolic measurements, however, pancreatic fat does not yet have an agreed clinical threshold that reliably distinguishes healthy from unhealthy levels.
What the Green Mediterranean Diet Study Found
The DIRECT-PLUS trial originally enrolled 294 adults with abdominal obesity or abnormal blood-fat levels, assigning them to one of three dietary approaches.
These included standard healthy dietary guidelines, a conventional Mediterranean diet and a modified version known as the Green Mediterranean diet, or Green-MED.
All three groups received physical activity support.
Researchers used abdominal MRI scans to examine pancreatic fat and pancreatic volume. Of the participants, 290 had eligible scans at the beginning of the study, while 233 completed follow-up imaging after 18 months.
The results showed a clear difference between the dietary groups.
Green Mediterranean diet: 14% relative reduction in pancreatic fat.
Conventional Mediterranean diet: 6.7% relative reduction.
Standard healthy dietary guidelines: 0.8% relative reduction.
The 14% figure describes the relative change in pancreatic fat, rather than a 14-percentage-point reduction or a fall in diabetes risk.
That is an important distinction when interpreting the findings.
The study also examined pancreatic volume. While the amount of fat decreased, researchers found no significant change in the organ’s measured volume across the groups.
This suggests that pancreatic fat can be reduced without a corresponding loss of overall pancreatic volume.
It does not, by itself, establish that individual insulin-producing cells were protected, but it provides useful evidence that changes in pancreatic fat and pancreatic size are not necessarily the same thing.
The Role of Walnuts, Mankai and Polyphenols
One of the most interesting aspects of the research concerns the foods associated with the greatest changes.
The Green Mediterranean diet placed particular emphasis on polyphenols, naturally occurring compounds found in plant foods.
Both Mediterranean diet groups consumed walnuts, while the Green-MED intervention also included green tea and Mankai, an aquatic plant used as a food ingredient.
Researchers reported that participants consuming more than three servings of Mankai each week, or more than 5.5 servings of walnuts, experienced greater reductions in pancreatic fat than those consuming smaller amounts.
The associations point towards a possible role for particular dietary components, although they do not prove that either ingredient independently caused the reduction.
That distinction is especially important with a dietary intervention involving several simultaneous changes.
The researchers also linked greater consumption of refined carbohydrates with smaller reductions in pancreatic fat.
That does not mean every slice of bread or bowl of pasta prevents the pancreas from losing fat. The findings concern dietary patterns and associations, not evidence that individual carbohydrate-containing foods universally cause harm.
As with our earlier guide to choosing bread when managing type 2 diabetes, it is important to distinguish between refined carbohydrates and higher-fibre alternatives rather than treating all carbohydrates as nutritionally identical.
Could Reducing Pancreatic Fat Improve Blood-Sugar Control?
Perhaps the most clinically relevant finding was the relationship between pancreatic fat reduction and markers of metabolic health.
Participants who experienced greater reductions in pancreatic fat also tended to show improvements in measures associated with insulin resistance.
The relationship remained evident after statistical adjustments for reductions in visceral fat, the fat stored deep within the abdomen.
That suggests pancreatic fat may provide information about metabolic health that cannot be explained entirely by changes in waist circumference or bodyweight.
However, statistical associations cannot establish that losing pancreatic fat directly caused the improvements.
The evidence for changes in HbA1c, a longer-term measure of blood glucose, was also less conclusive than the results for insulin resistance.
Professor Iris Shai, the study’s principal investigator at Ben-Gurion University of the Negev, believes the findings support greater attention to the pancreas when investigating metabolic health.
“Therefore, the pancreas is a target organ whose recovery helps blood-sugar balance well beyond the general loss of abdominal fat.”
The potential implications are considerable, but the study did not demonstrate that following the Green Mediterranean diet prevents type 2 diabetes or reverses an existing diagnosis.
What the Findings Mean for Everyday Eating
There are several reasons to take this research seriously.
DIRECT-PLUS was an 18-month randomised dietary trial, with supervised workplace lunches, exercise support and detailed MRI measurements. Its duration and imaging methods allowed researchers to examine changes that would be difficult to detect through weight measurements alone.
Nevertheless, this particular pancreatic-fat investigation was a secondary, exploratory analysis rather than a trial designed specifically to establish whether reducing pancreatic fat prevents diabetes.
The study population also limits how widely the findings can be applied. Participants were predominantly men, with an average age of approximately 51, and had abdominal obesity or abnormal blood-fat levels.
Consequently, the results cannot automatically be extended to younger adults, people without metabolic risk factors or every person living with diabetes.
Nor should the research be interpreted as a prescription to begin eating large quantities of walnuts or sourcing Mankai. The results reflect a wider dietary intervention, undertaken alongside physical activity, rather than a test of a single food.
For anyone already managing diabetes, substantial dietary changes should also be discussed with their healthcare team, particularly where medication could increase the risk of low blood sugar.
What the findings do offer is a more detailed understanding of how lifestyle changes may affect the body.
Previous DIRECT-PLUS research examined reductions in liver and abdominal fat. This latest analysis extends that investigation to the pancreas, suggesting that dietary quality may influence fat deposits in another organ closely involved in metabolic regulation.
For years, much of the conversation around improving metabolic health has centred on losing weight. This research suggests that the changes taking place inside the body deserve just as much attention as the number appearing on the scales.
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