What is the current thinking on the management and prevention of fatty liver disease?

Why Fatty Liver Disease is So Common: Current Understanding

Fatty liver disease has become epidemic because it is fundamentally the hepatic manifestation of metabolic syndrome, affecting 30% of adults in developed countries due to the convergence of obesity, insulin resistance, and Western dietary patterns. 1

The Core Pathophysiology

The prevalence is staggering and directly tied to metabolic dysfunction:

• NAFLD affects up to 90% of obese individuals and 50% of people with type 2 diabetes, making it the most common liver disease worldwide 1
• Patients with type 2 diabetes have up to 19% prevalence of advanced fibrosis—ten times higher than the general population—and almost 70% have NAFLD 2
• The global prevalence in children has risen from 4% in 1975 to 18% in 2016, with childhood obesity complications persisting into adulthood and increasing severe MAFLD at earlier ages 3

Why the Epidemic Exists: Dietary and Lifestyle Factors

The Western diet is the primary driver of this epidemic:

• Western dietary patterns rich in soda, frozen junk food, processed meats, whole fat dairy, and poor in whole grains, vegetables, and fish directly promote NAFLD development 1
• Specific macronutrients—saturated fatty acids, trans-fats, simple sugars (especially fructose), and animal proteins—have harmful effects on the liver 1
• Excess fructose consumption from processed foods and beverages is a key modifiable risk factor 1

The metabolic syndrome connection is critical:

• NAFLD is strongly associated with obesity, insulin resistance, type 2 diabetes, hyperlipidemia, hypertension, and metabolic syndrome 1
• The disease represents the hepatic manifestation of metabolic syndrome, making it inevitable in populations with high rates of these conditions 4

The Progression Risk

Not all fatty liver is benign—understanding progression is essential:

• NASH occurs in approximately 30% of NAFLD patients and significantly increases risk of cirrhosis, portal hypertensive bleeding, hepatocellular carcinoma, and hepatic decompensation 1
• NAFLD is predicted to become the main risk factor for hepatocellular carcinoma and has become a common indication for liver transplantation 1
• The presence of NASH (steatosis plus hepatocyte ballooning and lobular inflammation) is the key driver of fibrosis progression, not steatosis grade alone 5

Secondary Causes Often Overlooked

While metabolic syndrome dominates, secondary causes contribute:

• Hepatitis C virus infection, endocrinological diseases (especially hypothyroidism), certain medications (corticosteroids, amiodarone, methotrexate, tamoxifen), nutritional disorders, and genetic polymorphisms (PNPLA3, TM6SF2, MBOAT7) can promote fatty liver development 4, 5
• Alcohol consumption, even at low levels, doubles the risk for adverse liver-related outcomes in NAFLD patients 5

The Detection Gap

A critical problem is underdiagnosis:

• Liver health is seldom included in routine diabetes reviews despite the high prevalence of advanced fibrosis in this population 2
• Early detection of liver fibrosis offers a window of opportunity to prevent disease progression, yet systematic screening in high-risk populations remains uncommon 2

Common Pitfalls in Understanding Prevalence

The most important caveat: cardiovascular disease, not liver disease, is the main driver of mortality in NAFLD patients before cirrhosis develops, making comprehensive metabolic management essential beyond just liver-focused interventions 5, 6

The epidemic nature of fatty liver disease reflects our modern environment—sedentary lifestyles, ultra-processed food consumption, and the metabolic syndrome pandemic have created perfect conditions for this disease to flourish across all age groups.