This multicenter, double-blinded, randomized controlled trial aims to evaluate the effect of berberine in reducing visceral and liver adipose tissue among individuals with obesity and non-alcoholic fatty liver disease (NAFLD) in China.

The trial aims to evaluate the efficacy and safety of berberine treatment for obesity and NAFLD. Potential eligible patients will be recruited from 10-20 medical centers in China. After a 4-week run-in period with berberine, all the eligible participants will be randomized (1:1) to berberine 1.0 g per day plus lifestyle intervention (Arm A) or placebo plus lifestyle intervention (Arm B). The participants will be asked to attend the visit at least once every 2 months, and be followed up for 6 months.

Inclusion Criteria:

• Participants aged ≥18 years
• Participants with obesity (i.e., BMI ≥ 28 kg/m2) and abdominal obesity (i.e., waist circumference ≥85 cm in female or waist circumference ≥90 cm in male)
• Participants with NAFLD diagnosed by ultrasound, computed tomography or magnetic resonance imaging

Exclusion Criteria:

• Patients with established coronary heart disease, stroke, or peripheral arterial disease
• Patients diagnosed with diabetes or taking oral glucose-lowering drugs
• Patients with severely uncontrolled hypertension (i.e., SBP≥180mmHg and/or DBP ≥110mmHg)
• Excess alcohol consumption (i.e., alcohol ≥ 20 g/day in female or alcohol ≥ 30 g/day in male)
• Other causes of fatty liver disease, including alcohol or drug abuse, hepatitis B or C, autoimmune, hepatolenticular degeneration, total parenteral nutrition, inflammatory bowel disease, celiac disease, hypothyroidism, Cushing syndrome, β -lipoprotein deficiency, lipid atrophy diabetes, Mauriac syndrome, etc.
• Patients with thyroid disease, including hyperthyroidism or hypothyroidism
• Patients with cardiac insufficiency
• ALT or AST ≥ 3 times upper limit of normal, liver cirrhosis or hepatic insufficiency
• Patients with renal insufficiency: estimated glomerular filtration rate (eGFR) < 60 ml/(min×1.73m2)
• Patients who had weight loss surgery, or are currently taking drugs for weight loss, or plan to have weight loss surgery or drugs in the following 6 months
• Patients diagnosed with glucose-6-phosphate dehydrogenase (G6PD) deficiency
• Taking berberine or drug containing berberine in the past 1 month
• Any adverse reaction to berberine
• Severe constipation, diarrhea, and/or severe chronic intestinal diseases (e.g., ulcerative colitis, Crohn's disease, irritable bowel syndrome, etc.)
• Patients who had to use long-term or intermittent corticosteroids, immunosuppressants, antibiotics, or other drugs that affect inflammatory biomarkers
• Women who are pregnant or breastfeeding, or those who plan to be pregnant during the trial
• Patients with malignant tumors
• Patients with mental disorders, cognitive disorders, and/or other serious diseases
• Those who participated or have been participating other trials during the last 3 months
• Any other conditions that may hinder the compliance to the study intervention or follow-up visit

Data manager and statistician