A new study published in Nature Communications 1 has added momentum to the growing interest in fasting-mimicking diets (FMDs) as a tool for improving metabolic and liver health. While the research shows that periodic FMD cycles can reduce liver fat, improve insulin sensitivity, and modulate immune pathways even without significant weight loss, hepatology experts in India say the approach is promising but not yet ready for routine clinical use.
The study, led by researchers in Europe and the United States, examined the effects of repeated FMD cycles in adults and found consistent improvements in hepatic steatosis, insulin resistance, and metabolic flexibility. Notably, participants did not lose large amounts of weight, yet their liver biomarkers improved, suggesting new possibilities for managing non-alcoholic fatty liver disease (NAFLD) and metabolic dysfunction-associated steatotic liver disease (MASLD).
To understand the implications for patient care, MedBound Times connected with Dr. Sarada Pasangulapati, Consultant Medical Gastroenterologist and Hepatologist at Yashoda Hospitals, Hyderabad, who offered clinical context for these emerging findings.
The Nature study showed that even short cycles of fasting-mimicking diets could lower liver fat levels and improve markers linked to the development of fatty liver disease. According to the researchers, reductions in hepatic fat content occurred alongside improvements in glucose metabolism and insulin resistance, both key drivers of MASLD.
Dr. Pasangulapati agrees that the findings are encouraging.
“Fasting-mimicking diets can be considered in managing fatty liver disease,” she says. “Studies suggest that even a few cycles can reduce liver fat and improve insulin resistance. By lowering fat in the liver and supporting better metabolism, these diets may help slow the shift from simple fatty liver to more serious liver conditions.”
However, she notes that FMD should not replace standard recommendations. “When paired with healthy eating and regular monitoring, FMD can be a useful addition to lifestyle advice for patients.” she adds
The Nature study’s most striking finding was that participants experienced metabolic and liver improvements despite minimal weight loss. The researchers observed reductions in liver fat fraction, improved insulin sensitivity, and changes in immune-related gene expression independent of major changes in body mass.
This challenges traditional clinical emphasis on weight loss as the primary marker of progress.
“The study shows that liver fat and metabolic health can improve even without major weight loss.” Dr. Pasangulapati explains. “This is an important shift. It means we should not rely only on body weight or BMI to assess liver health.”
She underscores the need to prioritize internal markers:
“Measures like liver-fat fraction, insulin resistance, and inflammation markers give a clearer picture. Fasting-mimicking diets seem to benefit the liver and metabolism even when external weight changes are small.”
While the study supports metabolic benefits of FMD in general populations, it does not evaluate high-risk groups, such as patients with cirrhosis or those recovering from endoscopic weight-loss procedures.
Dr. Pasangulapati advises caution.
“Fasting-mimicking diets can help in early or mild fatty liver disease, but their safety in advanced cases like cirrhosis has not been studied.” she says. “For patients undergoing endoscopic weight-loss procedures, strict calorie restriction may increase the risk of malnutrition or slow recovery.”
Her clinical recommendation:
“Until strong evidence is available, I would not recommend routine FMD use in advanced liver disease. Personalized diet and medical care remain the safer approach.”
One of the intriguing aspects of the Nature study is its finding that FMD cycles influenced immune-regulatory pathways, including T-cell activation and gene-expression signatures associated with inflammatory control. The authors suggest that metabolic improvement may help restore immune equilibrium.
But translating this into clinical guidance for liver-disease patients remains premature.
“Fasting-mimicking diets may help rebalance immunity in liver disease by improving certain markers.” says Dr. Pasangulapati. “This suggests they could support immune resilience, but caution is needed.”
She notes that liver-disease patients often have compromised immunity.
“In patients with chronic liver problems or weak immunity, such diets must be studied more carefully. Larger, disease-specific trials are required before recommending FMD purely for immune benefits.”
Despite promising data, FMD is still far from becoming a standard gastro-hepatology recommendation.
“We need large, long-term trials in diverse patients, including those with liver disease.” Dr. Pasangulapati emphasizes. “We must test safety, sustainability, effects on muscle health, and impact on liver fibrosis over time.”
Comparative studies are also essential.
“Studies comparing FMD with standard lifestyle changes like diet and exercise will show if it truly adds benefit. Only then can it be recommended widely in gastro-hepatology practice.”
Fasting-mimicking diets offer a promising non-pharmaceutical option rooted in metabolic science, but hepatologists urge grounded expectations.
Reference:
1. Brandhorst, Sebastian, Morgan E. Levine, Min Wei, Mahshid Shelehchi, Todd E. Morgan, Krishna S. Nayak, Tanya Dorff, Kurt Hong, Eileen M. Crimmins, Pinchas Cohen, et al. “Fasting-Mimicking Diet Causes Hepatic and Blood Markers Changes Indicating Reduced Biological Age and Disease Risk.” Nature Communications 15 (2024): Article 1309.https://www.nature.com/articles/s41467-024-45260-9
