Israeli study suggests fat loss ‘memory’ could change how doctors treat obesity

Losing belly fat may deliver benefits that last far longer than previously thought — even if the weight eventually returns, according to a major Israeli study that challenges conventional thinking about dieting success.

The study, by a team of researchers at Ben-Gurion University of the Negev, suggests that the location of fat loss matters more than the number on the scale. Scientists found that reducing visceral fat — the deep abdominal fat surrounding internal organs — was strongly linked to lower long-term risk of type 2 diabetes, even years after the original lifestyle intervention ended. It also reinforces growing evidence that internal fat distribution is a better predictor of metabolic disease than Body Mass Index (BMI) alone.

Dr Hadar Klein, the study’s lead author, told The Press Service of Israel that the findings suggest lifestyle changes may leave a lasting biological imprint.

“Our findings suggest that the body may retain a long-term cardiometabolic memory of visceral fat loss,” said Klein, RD, MSc and PhD candidate. “Even after participants regained their body weight, the reduction in visceral fat achieved during the 18-month lifestyle intervention was partly preserved and remained associated with better long-term metabolic health.”

She explained, “This means that weight regain does not necessarily equal complete metabolic relapse. A successful period of healthy lifestyle may leave a protective physiological imprint that persists for years.”

The study, published in the peer-reviewed journal Circulation, followed 366 participants from the CENTRAL and DIRECT-PLUS dietary trials, conducted by the university in partnership with international researchers. Participants underwent 18 months of structured dietary and exercise programs and were then tracked for up to a decade, with repeat Magnetic Resonance Imaging (MRI) scans measuring fat distribution in detail.

Using high-resolution 3.0-Tesla MRI scans, researchers tracked visceral fat alongside liver fat, pancreatic fat, and subcutaneous abdominal fat.

The metabolic impact was significant. Each 10% reduction in visceral fat during the intervention was associated with roughly a 30% lower risk of developing type 2 diabetes in later years. Larger reductions showed even stronger protection, with a 20% reduction linked to nearly a 50% drop in risk.

While participants regained much of their lost weight over time, visceral fat levels remained lower than baseline. Liver fat returned to starting levels, and pancreatic fat even increased beyond baseline.

Researchers say the findings could influence clinical practice, encouraging doctors to monitor waist circumference more closely and to view visceral fat as a therapeutic target rather than a hidden byproduct of weight loss efforts. This could shift success metrics beyond BMI toward abdominal fat distribution.

“In routine clinical practice, waist circumference should be used more consistently as a simple and accessible marker of abdominal fat and cardiometabolic risk. When feasible, direct assessment of visceral fat would be even better,” Klein said. However, MRI and Dual-Energy X-ray Absorptiometry (DXA) scans are not feasible on an everyday basis.

“We need to develop more accessible, affordable, and scalable methods to estimate visceral fat and monitor changes over time,” she told TPS-IL.

Klein cautioned that the results currently apply only to lifestyle interventions. She told TPS-IL that it remains unknown whether weight-loss medications produce the same effect. Future research, she said, must determine “whether they also produce durable visceral fat loss.”

But the immediate next step, she said, “is to translate these findings into clinical practice and to understand the underlying biology.”

Klein stressed that while BMI, a screening tool that estimates whether a person has a healthy weight by comparing their weight to their height, remains useful, “it should no longer be the only central measure of success.”

By Pesach Benson and Omer Novoselsky/TPS-IL