Clinical and Epidemiological Interpretation of the 2025 AASLD Practice Statement on the Evaluation and Management of MASLD in Children

Read this article in Spanish: MASLD en pediatría: del “hígado graso” a un síndrome cardiometabólico que exige acción temprana

MASLD (Metabolic dysfunction–Associated Steatotic Liver Disease) is the term that now replaces the former designation NAFLD (Non-Alcoholic Fatty Liver Disease). It refers to steatotic liver disease associated with metabolic dysfunction: fat accumulation in the liver occurring in individuals with metabolic abnormalities in whom alcohol consumption does not explain the hepatic injury.

Not all children with overweight or obesity develop MASLD, although the risk increases significantly. Obesity is the main risk factor, but it is not synonymous with steatotic liver disease. Current estimates suggest that up to 50–60% of children with severe obesity may develop MASLD.

The diagnosis of MASLD requires evidence of hepatic steatosis — identified through ultrasound, elastography, MRI, or histology — together with at least one criterion of metabolic dysfunction such as overweight or obesity, type 2 diabetes, insulin resistance, dyslipidemia, hypertension, or metabolic syndrome. In pediatrics, MASLD is closely linked to childhood obesity, hyperinsulinemia, and early disruption of metabolic pathways.

The pathophysiology of MASLD is complex and multifactorial. It is currently described under the “multiple hits hypothesis,” involving insulin resistance, lipotoxicity, inflammation, and progression to MASH when steatosis is accompanied by inflammation and hepatocellular injury. In that case, we refer to MASH (Metabolic dysfunction–Associated Steatohepatitis), the modern equivalent of the former NASH terminology. Additional contributors include the gut-liver axis, genetic and epigenetic influences, and polymorphisms that modulate disease risk and progression.

There is no universal pharmacologic cure. Treatment remains comprehensive and stepwise, centered primarily on lifestyle intervention, management of comorbidities, pharmacologic therapy in selected cases, and advanced care strategies when significant fibrosis or high-risk disease is present.

The AASLD Practice Statement on the Evaluation and Management of Metabolic Dysfunction–Associated Steatotic Liver Disease (MASLD) in Children (Hepatology; Epub April 29, 2025; print publication November 2025) is fundamentally a normative document. It is not a clinical trial, cohort study, or primary meta-analysis; rather, it is an expert synthesis of available evidence organized into clinically applicable recommendations for real-world practice. Published in Hepatology 2025;82(5):1352–1394, the document clearly establishes its pediatric focus.

From an epidemiological perspective, documents of this type are evaluated according to the clarity of the public health problem they address, the transparency with which evidence is prioritized, the operational definitions they use, the practicality of their diagnostic algorithms, and, most importantly, their feasibility of implementation without causing net harm through overdiagnosis, stigma, excessive testing, or iatrogenic consequences.

The statement’s first epidemiological strength lies in its premise of urgency: MASLD can no longer be treated as a rare subspecialty condition. In a high-level review presented at DDW 2025, co-chair Jeffrey Schwimmer summarized two important figures that help frame the magnitude of the problem and the cost of inaction: approximately 10% of children may have MASLD, and among those referred to pediatric gastroenterology who complete diagnostic evaluation, nearly 15% already demonstrate stage 3 fibrosis. Epidemiologically, this is an alarming combination: a disease with meaningful population prevalence and a subgroup already presenting with advanced progression detected too late.

The document therefore aligns with a classic secondary prevention framework: if a detectable subclinical phase exists, and if the natural course of disease can be modified through intervention, risk stratification, or management of comorbidities, then systematic screening may be justified from a public health standpoint.

Its second major strength is conceptual and particularly relevant to pediatrics: MASLD is not presented as “a liver disease,” but rather as a multisystem cardiometabolic condition requiring integration between primary care, nutrition, mental health, endocrinology, cardiology, and hepatology when necessary. Clinically, this is accurate, and epidemiologically it reflects what is already known about risk clustering: obesity, insulin resistance, dyslipidemia, hypertension, sleep disorders, and mental health conditions frequently coexist. Treating the liver in isolation misses opportunities for global risk reduction. By design, the statement attempts to break healthcare fragmentation and encourage coordinated care pathways rather than isolated referrals for elevated ALT levels.

One of the statement’s most practical — and also most debated — recommendations concerns screening in primary care. According to the DDW summary, primary care providers should screen all children with overweight or obesity for MASLD beginning at age 10, unlike adult strategies that generally reserve screening for those with additional high-risk factors. From an epidemiological perspective, this implies accepting a trade-off: broader screening increases population sensitivity and case detection at the cost of more false positives and greater follow-up burden.

In pediatrics, however, the threshold for accepting this trade-off may reasonably be lower if delayed diagnosis carries substantial harm, including advanced fibrosis and worsening cardiometabolic trajectories, and if the initial screening test is inexpensive and accessible. In that context, the statement maintains that ALT remains the best validated screening tool in pediatrics when interpreted using pediatric-specific thresholds.

This point is critical. ALT is accessible, but imperfect as a population screening test. Its positive predictive value depends heavily on the prevalence within the subgroup being tested. Ordering ALT universally in school populations is not equivalent to targeted screening among children with obesity or metabolic comorbidities. In practice, the statement positions ALT as an entry point while emphasizing the need for comprehensive evaluation before attributing elevated liver enzymes solely to MASLD.

The document also acknowledges two epidemiological realities that are essential to avoid clinical bias. First, not every child with obesity will develop MASLD. Publicly presented data suggest that roughly one in four children with obesity may have MASLD. Equating obesity automatically with fatty liver disease risks overdiagnosis, unnecessary stigma, and dilution of resources away from those truly at hepatic risk.

Second, MASLD can occur in children with normal BMI. Approximately 30% of children with steatotic liver disease may present with normal BMI, underscoring the importance of assessing the complete phenotype: fat distribution, family history, ethnicity, insulin resistance, and dyslipidemia rather than relying exclusively on BMI. Epidemiologically, this highlights the limitations of weight-centered prevention models and reminds us that BMI alone cannot capture the entire at-risk population.

Regarding confirmatory diagnosis, the statement identifies MRI–Proton Density Fat Fraction (MRI-PDFF) as the best validated noninvasive technique for quantifying hepatic steatosis in pediatric populations, while recognizing that access remains limited in many healthcare environments. Alternative imaging approaches and selected scenarios for liver biopsy are also discussed.

From an applied epidemiology perspective, this raises important equity concerns. If ideal recommendations depend upon advanced technologies that are not universally available, healthcare systems risk creating a “two-speed medicine” model. The strength of the statement is that it remains pragmatic rather than purely aspirational. The challenge for clinicians will be avoiding two extremes: doing nothing because MRI-PDFF is unavailable, or overreacting with premature invasive testing due to uncertainty.

The therapeutic section of the statement remains deliberately cautious. At present, no medications are specifically approved for pediatric MASLD or MASH. Therefore, the cornerstone of treatment remains intensive lifestyle intervention with a family-based multidisciplinary approach.

Scientifically, this is a responsible conclusion, but it exposes an operational gap frequently encountered in public health. Lifestyle intervention often fails when delivered as generic advice rather than as a structured, measurable, and monitored program. The statement attempts to address this limitation by emphasizing multidisciplinary care and inclusion of mental health support, recognizing that successful outcomes depend on adherence, family dynamics, food insecurity, cultural context, sleep quality, stress, and access to safe opportunities for physical activity.

From a pediatric perspective, this point is fundamental: children rarely control their own environment. Therefore, treatment often becomes treatment of the family system and the school and community environment as much as treatment of the child.

The statement also acknowledges an important evidence gap: children have historically been excluded or underrepresented in trials evaluating emerging MASLD therapies. As a result, the document calls for dedicated pediatric clinical trials and improved noninvasive biomarkers. Epidemiologically, this serves as a caution against simply extrapolating adult data into pediatric populations. Therapies effective in adults with MASH may not demonstrate the same safety or benefit profile in adolescents undergoing growth and pubertal development.

Overall, the AASLD Practice Statement fulfills a critical public health role. It translates a prevalent and progressive disease into an actionable framework that can begin in primary care and coordinate with subspecialty services. Its strengths include defining MASLD as a multisystem disease, recommending early integrated screening during pediatric care, prioritizing ALT with pediatric-specific thresholds, recognizing the limitations of adult algorithms, and proposing realistic diagnostic and therapeutic pathways without overpromising nonexistent pediatric pharmacologic solutions.

Its points of tension — where clinicians must apply careful judgment — involve the risk of overdiagnosis when ALT is interpreted without clinical context, technological inequities surrounding MRI-PDFF confirmation, and the challenge of transforming “lifestyle modification” from a moral recommendation into a structured, measurable intervention.

From a comprehensive pediatric perspective, the final message is unmistakable: we cannot wait until these children become adults before recognizing their disease. If a meaningful proportion are already reaching specialty care with advanced fibrosis, then the window for secondary prevention is closing far too early.

Ismael Perdomo, MD
Pediatrician – Epidemiologist
Founder & CEO, With Ties of Love Inc.
Orlando, Florida, United States