Parental Obesity Linked to Increased Child Liver Disease Risk: Study

A person’s risk of developing metabolic dysfunction-associated steatotic liver disease (MASLD), the most common form of liver disease, is significantly linked to the body mass index (BMI) of their parents, according to a new study published in February 24, 2026 in the journal Gut. The research, conducted by scientists at Washington University School of Medicine in St. Louis, suggests that preventative measures could begin even before conception.

The study analyzed data from the UK Avon Longitudinal Study of Parents and Children (ALSPAC), tracking nearly 2,000 individuals from birth through age 24. Researchers found that for each unit increase in a parent’s BMI during the first trimester of pregnancy, the child’s risk of developing MASLD by their 20s increased by up to 10%. Importantly, the study revealed that both maternal and paternal obesity contribute to this increased risk.

“This changes how we think about obesity and obesity-related disease,” said Yin Cao, ScD, an associate professor of surgery at WashU Medicine and senior author of the paper. “We often oversimplify this topic by talking only about a patient’s current BMI as the driving factor for disease, but here we are showing the risk factors for this liver disease may actually emerge years earlier, from the parents.”

Parental BMI and Offspring Risk

MASLD, previously known as non-alcoholic fatty liver disease, is characterized by a buildup of fat in the liver, potentially leading to inflammation, scarring, and liver failure. It currently affects almost 40% of adults in the U.S., with projections estimating that number will rise to 55% by 2040.

The study quantified the increased risk associated with parental weight. Maternal obesity was linked to a 2.9-fold increase in the odds of MASLD in offspring, while paternal obesity was associated with a 1.7-fold increase. When both parents were overweight or obese, the risk more than tripled. The researchers found that cumulative excess weight in childhood also played a significant role in how much parental obesity contributed to the child’s risk.

While previous research highlighted the connection between maternal obesity and MASLD risk in children, this study establishes a clear link to paternal BMI as well. This finding underscores the importance of considering both parents’ health when assessing a child’s risk.

Understanding the Mechanisms

Stefani Tica, MD, an assistant professor of pediatrics, gastroenterology, hepatology and nutrition at WashU Medicine and the first author on the study, noted that MASLD often remains undiagnosed, particularly in younger patients, due to a lack of noticeable symptoms. “It’s not uncommon for young adults who come in to see us to have a fair amount of scarring of their liver already that had been smoldering for quite some time,” she said, adding that MASLD is a leading cause of liver transplants.

The researchers acknowledge that further investigation is needed to fully understand the mechanisms driving this intergenerational link. Potential pathways include obesity-related changes to the gut microbiome – the community of microorganisms living in the digestive tract – and alterations in gene expression that may be passed down from parents to children.

Implications for Prevention

The study’s findings suggest that addressing obesity in prospective parents could be a crucial step in reducing the incidence of MASLD in future generations. Cao emphasized the need to broaden prevention and education efforts to include preconception care, pregnancy, and childhood.

“This indicates a need to better define obesity’s intergenerational impact and to concentrate more of our prevention and education efforts to earlier in life,” Cao explained.

Beyond the direct health risks associated with liver disease, Cao also pointed out its connection to certain cancers, including liver and colorectal cancer, which is increasingly diagnosed in younger adults. She highlighted the rarity of studies that track individuals from birth to young adulthood, emphasizing the importance of long-term research to capture the gradual development of chronic diseases.

Without interventions to address rising obesity rates, Cao warned, “we are going to see more diseases like MASLD in younger ages, because obesity is carrying these potential impacts forward, generation to generation, and amplifying them.”

This research was supported by grants from the National Institute of Diabetes and Digestive and Kidney Disorders, the Wellcome Trust, and the UK Medical Research Council.