According to Dr. Bui Thi Thuy from the Department of Adult Nutrition Consultation at the National Institute of Nutrition, non-alcoholic fatty liver disease (NAFLD) occurs when fat accounts for more than 5% of the liver’s weight in people who consume little or no alcohol and have no other secondary causes such as viral infections, certain medications, or metabolic disorders.

NAFLD affects an estimated 25–30% of the global population, with higher rates among people with obesity, type 2 diabetes, and dyslipidemia. In Vietnam, cases are rising sharply due to increasing obesity rates and sedentary lifestyles. The disease is linked to insulin resistance and lipid and glucose metabolism disorders, which lead to triglyceride buildup in the liver. Over time, this can cause oxidative damage, inflammation, mitochondrial dysfunction, hepatitis, and liver fibrosis.

Since no drug treatment is currently available, early intervention through diet, exercise, healthy weight maintenance, and adequate sleep offers the best protection against liver damage.

A central principle is to limit fat intake. Replace saturated and trans fats with unsaturated fats, particularly omega-3 fatty acids, to reduce the risk of cardiovascular disease. Saturated fat should account for less than 7–10% of daily energy intake. Adults should consume about 45–60 grams of fat per day, or 20–25% of total daily energy.

Healthy fat sources include 20–25 grams of vegetable oils daily (around two tablespoons) and 15–20 grams of nuts such as walnuts, almonds, and sesame seeds. Fatty fish such as salmon, mackerel, and sardines should be eaten two to three times a week to boost omega-3 intake, which benefits both the heart and liver.

Carbohydrates should come mainly from low-glycemic index (GI) foods such as leafy greens, whole grains, legumes, and certain fruits including pears, oranges, apples, guavas, and grapefruit. Recommended daily portions include 300–350 grams of white or brown rice (equivalent to two to 2.5 bowls per meal for two meals), two to three slices of whole-grain bread, and 100–150 grams of boiled sweet potato or potato. Adults should also have two to three servings of fresh fruit daily, with each serving weighing 80–100 grams.

Reduce consumption of foods and drinks high in simple sugars, especially fructose found in soft drinks, sports drinks, sweetened tea, and fruit juices. Sugar should make up no more than 10% of daily energy intake, ideally under 5%—about 25 grams per day for adults.

Avoid animal organs such as liver, intestines, heart, and brain, which are high in cholesterol, as well as fast food and processed products that often contain excessive salt and unhealthy fats. Alcohol should be completely avoided, as it can cause severe liver damage and worsen NAFLD.

Beyond diet, lifestyle factors also affect disease progression. Staying up late disrupts the body’s biological rhythm, lowers sleep quality, and increases inflammation. Adults should aim for seven to eight hours of sleep per night.

Engage in regular physical activity—at least 30 minutes a day, five days a week. Drink 1.5–2 liters of water daily, and limit sugary and carbonated drinks. Regularly monitor liver enzyme levels and follow medical advice to track and manage the condition effectively.