Significant visceral fat loss may protect metabolic health even after weight regain

A long-term magnetic resonance imaging study has suggested that lifestyle-induced visceral fat loss may leave a durable cardiometabolic benefit, even when participants regain body weight years after dietary intervention

Lifestyle-induced loss of visceral fat, rather than liver fat, pancreatic fat or subcutaneous fat, may confer lasting health benefits years after the end of an intervention, even when body weight has returned to baseline, according to researchers from Ben-Gurion University of the Negev, Beersheba, Israel and international collaborators.

The findings have suggested that a reduction in visceral fat, the harmful intra-abdominal fat stored deep in the abdomen around internal organs, may be partly preserved in the long term and may be associated with better cardiometabolic health and a lower future risk of type 2 diabetes (T2DM).

The study tracked 366 participants from the original clinical trial cohorts with magnetic resonance imaging (MRI) and achieved a reported 96 per cent retention rate across a decade. The researchers said this had enabled the first large-scale assessment of how specific internal fat depots behaved over time after a long-term lifestyle trial.

By long-term follow-up, body weight had returned to baseline on average. However, waist circumference and abdominal fat depots, including visceral fat, deep subcutaneous fat and superficial subcutaneous fat, remained lower than baseline. Liver fat also returned to baseline while pancreatic fat increased above baseline.

The most clinically important finding was that each 10 per cent reduction in visceral fat achieved during the original intervention was independently associated with an approximately 30 per cent lower risk of T2DM during long-term follow-up. Visceral fat reduction was also associated with sustained improvements in insulin resistance, a composite cardiometabolic risk score and metabolic syndrome severity. These associations remained significant after the researchers had accounted for weight change, diet adherence, physical activity and other clinical factors measured at follow-up.

“These findings challenge the traditional narrative that weight regain equals clinical failure because the human body retains a cardiometabolic memory of visceral fat loss.

“This durable target protects against systemic ageing and metabolic decay long after a diet ends, suggesting that every successful period of healthy living leaves behind a mark of protection within the visceral fat cells.

“Our findings indicate that visceral fat reduction, rather than weight loss alone, may be a key target for long-term cardiometabolic health and lower future T2DM risk,” said Professor Iris Shai, principal investigator of the study from Ben-Gurion University of the Negev, dean of the School of Sustainability at Reichman University, adjunct professor at Harvard T.H. Chan School of Public Health and honorary professor at Leipzig University in Germany.

The study was based on the Follow Interventions Trials (FIT) project, a long-term follow-up of participants from two 18-month randomised controlled dietary trials, CENTRAL and DIRECT-PLUS. These trials assessed lifestyle strategies that included low-fat dietary guidance, healthy dietary guidance and variants of the Mediterranean diet, including standard, low-carbohydrate and polyphenol-enriched ‘green’ Mediterranean diets. The interventions also incorporated structured physical activity.

Researchers invited participants to attend repeat clinical assessments and MRI scans five and 10 years after the trials had ended. They measured visceral fat, deep subcutaneous fat, superficial subcutaneous fat, liver fat and pancreatic fat to determine whether changes in these depots persisted and whether they predicted later metabolic outcomes.

The FIT study has moved beyond the limitations of body mass index (BMI) by mapping hidden internal fat pools with high-resolution imaging. The researchers used high-field 3.0-Tesla MRI to quantify deep abdominal fat layers and to separate abdominal fat into visceral, deep subcutaneous and superficial compartments. The same method also allowed them to quantify ectopic fat deposits in the liver and pancreas, which are often implicated in metabolic disease.

“Our findings suggest that not all weight loss is equal. Reducing visceral fat may have a more lasting impact on metabolic health than changes in body weight alone, and may help support healthier ageing over time,” said Hadar Klein, the lead author on the study, who is also a registered dietitian and doctoral candidate.

Visceral fat is increasingly recognised as a central driver of insulin resistance, dyslipidaemia and cardiometabolic disease. In this study, it was the only fat deposit whose loss consistently predicted lower future T2DM risk. A five per cent reduction in visceral fat was linked to a 17 per cent lower risk, a 10 per cent reduction to a 30 per cent lower risk, a 15 per cent reduction to approximately a 40 per cent lower risk and a 20 per cent reduction to nearly a 50 per cent lower risk.

Other fat depots, including deep and superficial subcutaneous fat and fat stores of the liver and pancreas, showed some association with later metabolic markers but not with future diabetes risk. The findings therefore suggest that visceral fat may be a more durable and clinically meaningful therapeutic target than weight change alone.

The trials were conducted at Ben-Gurion University of the Negev with researchers from Harvard University, Cambridge, MA, and Tulane University, New Orleans, both in USA, Leipzig University, in Germany, in collaboration with the Dimona Nuclear Research Center, Briuta Medical Center and Soroka University Medical Center all in the Negev region of Israel.

For further reading please visit: 10.1161/CIRCULATIONAHA.125.079009