The Effect of Vegetarian Diet on Patients With Metabolic Associated Fatty Liver Disease

The Effect of Vegetarian Diet on Patients With Metabolic Associated Fatty Liver Disease：A Randomized Clinical Trial

In this study, 18-60 years old patients with metabolic associated fatty liver disease（MAFLD） will be recruited to test the intervention effect of vegetarian diet. This randomized clinical trial randomized individuals to a healthy vegetarian diet or a healthy omnivorous diet for 24 weeks. At the baseline and after the 24week intervention, the clinical manifestations of MAFLD, obesity levels, indices for glucose and lipid metabolism parameters, results of questionnaire and fecal samples will be collected and analyzed.

Dietary control remains an important way for nutritional intervention of metabolic related fatty liver disease. However, studies shows that patients have low compliance to the traditional diet. The topic proposed based on previous studies，recruiting of 220 obesity patients with metabolic associated fatty liver disease aged 18-60. After the informed consent, they will be randomly divided into intervention group and control group, intervention group will be given healthy vegetarian diet intervention and the control group given healthy omnivorous diet. Both diets are in line with the principles of fatty liver treatment. Interventions consisted primarily of face-to -face interview monthly and online interview every 2 weeks, which will be performed by professional dietitians. All participants were asked not to alter their exercise patterns during the study period. The primary outcome was the weight of fat mass after 24 weeks intervention. Secondary outcomes included imaging findings (B-ultrasonic examination and Fibroscan) of MAFLD, liver function, anthropometric measures, plasma lipid and glucose levels. At the meantime, serum oxidative stress indices, results of compliance survey and metabolites of Intestinal flora will be collected and analyzed. Through the above detection of the indicators related to MAFLD and obesity, it is explored whether the vegetarian diet can be an efficient and feasible way to the nutritional therapy of MAFLD.

Participations in this group are required to follow a healthy vegetarian diet （avoid meat, poultry, fish, dairy） during the 24-weeks trail. Daily energy intake = BMR(basal metabolic rate) × 1.25-500kcal；BMR = 370 + 21.6 × Lean body mass(kg) Requirements of energy supply ratio: protein 15%-20%; fat 20%-25%; carbohydrate 50%-60%.

Participations in this group are required to follow a healthy omnivorous diet (No restriction on food sources) during the 24-weeks trail. Daily energy intake = BMR × 1.25-500kcal；BMR = 370 + 21.6 × Lean body mass(kg) Requirements of energy supply ratio: protein 15%-20%; fat 20%-25%; carbohydrate 50%-60%.

Dietary guidance will be given to participants through monthly face-to-face interviews and biweekly telephone calls to change their dietary structure and energy intake.

Weight loss, especially the reduction of body fat mass, is the most important treatment for the prevention and treatment of MAFLD and its complicationsIn our study, we will measure weight of fat mass using a body composition analyzer (Biospace Inbody 720, Korea) at the baseline and after 24-week intervention. The difference in the weight of fat mass after intervention between the two groups is the primary outcome.

Imaging examination results are an important basis for the clinical diagnosis of NAFLD, which can show the degree of hepatic steatosis and hepatic fibrosis. Imaging findings of MAFLD will be measured and compared at the baseline and end of our study.

The 24-week intervention is expected to bring weight loss. We will compare the weight loss between the two groups

We have designed a compliance scale to evaluate the compliance , which may be important to advise the nutritionists and doctors about the prevention and treatment of MAFLD.

The difference of serum superoxide dismutase (SOD) level between two groups after 24-week intervention

Cause vegetarian diet may contain more phytochemicals and less saturated fat and cholesterol due to the plant-based nature of the diet, resulting in better metabolic status and milder metabolic burden,we have presumed that the serum SOD level be different between two groups at the end of study.

The fecal samples before and after the intervention to examine the effect of vegetarian diets on gut microbiota metabolites.

Inclusion Criteria: Clinically diagnosed as fatty liver, and BMI≥24.0kg/m²; 18-60 years old; Have not received drug treatment if having hyperglycemia, hyperlipidemia and high uric acid ; No antibiotics in the last 1 month; The guardian's informed consent; Exclusion Criteria: Have received drug treatment of fatty liver disease within three months; Patients with with liver cirrhosis, viral hepatitis and other liver diseases; Patients with serious heart, lung, kidney diseases and patients with cancer; Pregnant and nursing women; Other conditions that may affect the results of the study

Department of Clinical Nutrition, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine