A Hepatologist’s Warning: Fatty Liver in Children Is Rapidly Increasing — Is Sugar, Snacks, and Juice to Blame?

1．The Truth About Fatty Liver: The Cause Is Not Just Alcohol

In recent years, approximately 1 in 3 Japanese adults is said to have fatty liver. While fatty liver was once thought to mean “too much alcohol,” Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)—caused by factors other than alcohol—is now rapidly increasing.

The Greatest Cause of This Modern Disease Is “Excess Sugar”

Hepatology specialists consider excess sugar consumption the greatest cause of fatty liver. Unconsumed fat and glucose are converted in the liver to triglycerides and accumulated. Particularly, “fructose found abundantly in juice, soft drinks, and fruit converts to fat directly in the liver more easily than glucose,” making it especially concerning.

Anyone Can Be at Risk

Fatty liver can develop even in elementary school children, regardless of drinking habits or sex. Even those who appear thin can accumulate fat if they have extremely low muscle mass (“hidden obesity”), reducing metabolism. Thin-type fatty liver is prone to progress to MASH (Metabolic Dysfunction-Associated Steatohepatitis) and increases risk of advancing to cirrhosis and liver cancer.

2．Liver SOS Signals and Progression Risk

Because the liver has high reserve capacity, even as disease progresses it often only manifests as vague discomfort such as general fatigue or ease of tiring. When decompensated cirrhosis (end-stage condition) develops, serious life-threatening symptoms appear.

Main Dangerous Signs at Advanced Stage

• Jaundice (skin or whites of eyes turn yellow)
• Ascites and edema
• Hepatic encephalopathy (decreased concentration, daytime drowsiness, hand tremors)
• Palmar erythema and spider angiomata
• Hematemesis and tarry stools (melena)

3．Lifestyle Habits to Improve Fatty Liver Starting Today

① “Gentle Low-Carb” Diet and Smart Eating Habits

Rather than cutting out all carbohydrates, “gentle low-carb” is recommended. Eating slowly reduces early satiety risks; chewing each bite approximately 30 times helps prevent overeating consciously.

Foods that help the liver: dietary fiber (vegetables, mushrooms, seaweed) to moderate glucose absorption. Quality protein from blue-backed fish (omega-3 fatty acids) and soybean products is effective. 1–2 cups of coffee daily has been shown in research to “suppress liver inflammation” through chlorogenic acid.

② Sustainable Exercise Habits

Aerobic exercise such as walking or light jogging, 3 times per week for approximately 30 minutes. “Brisk walking” at a pace that makes you lightly perspire is optimal for physical improvement and fat burning. Resistance training to increase muscle mass and raise basal metabolism is also effective.

4．The Next Step Toward a Future That Doesn’t Give Up

Accurate Diagnosis by a Hepatology Specialist

If values don’t improve after lifestyle changes, this may be a sign of progression to MASH or cirrhosis. Blood tests alone make it difficult to determine fat accumulation or fibrosis in the liver. Abdominal ultrasound (echo) examination can painlessly confirm fat severity and signs of fibrosis.

Don’t Give Up Hope Even After a Cirrhosis Diagnosis

Conventional treatment makes it difficult to completely restore a once-hardened liver. Liver transplantation is the only radical treatment, but donor shortage is a challenge. Currently, liver regenerative medicine using stem cells is attracting attention as new hope.

Our clinic works on therapy (autologous adipose-derived stem cell infusion therapy) infusing stem cells cultivated from the patient’s own buttock fat tissue. Stem cells are expected to potentially promote suppression of liver inflammation, suppression and improvement of fibrosis progression, and repair and regeneration of remaining liver cells.