Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) in childhood is becoming increasingly prevalent, paralleling the rise in obesity rates, and has become the most common chronic liver disease in the pediatric population. MASLD is associated with metabolic mechanisms such as insulin resistance, dyslipidemia, oxidative stress, and inflammation, and can progress to serious complications like steatohepatitis, fibrosis, and cirrhosis in later stages. Currently, pharmacological treatments for managing MASLD are limited, and lifestyle modifications, particularly dietary interventions, stand out as the primary approach for preventing and treating the disease. In this context, the composition of macro and micronutrients plays a critical role in the development and progression of hepatic steatosis.

Within this framework, the Dietary Approaches to Stop Hypertension (DASH) diet is a balanced eating pattern that encourages the consumption of vegetables, fruits, whole grains, legumes, low-fat dairy products, fish, poultry, and healthy fat sources, while limiting sodium, saturated fat, sugary foods, and processed meat products. Similar to the Mediterranean diet, the DASH diet is a promising approach for conditions like metabolic syndrome and MASLD due to its anti-inflammatory potential, its reducing effect on oxidative stress, and its properties that enhance insulin sensitivity. Furthermore, thanks to its high fiber content, it contributes to balancing the gut microbiota and supports the production of short-chain fatty acids (SCFAs), which in turn have positive effects on liver and metabolic health.

Evaluated in terms of fat intake, the DASH diet's emphasis on foods rich in n-3 fatty acids (such as fish and walnuts) provides an anti-inflammatory effect, while limiting saturated and trans fats offers an important strategy for reducing hepatic fat accumulation. Additionally, restricting the consumption of added sugars and fructose may be effective in preventing hepatic steatosis by suppressing lipogenesis processes.

In light of all these scientific findings, considering the impact of dietary patterns on the development and progression of MASLD, appropriately structuring the diet is critically important for protecting liver health in children. Accordingly, an anti-inflammatory, antioxidant, and metabolically balanced DASH dietary model is considered an effective and applicable approach in the management of pediatric MASLD.

Within the scope of this study, the effects of implementing the DASH diet in children with MASLD on clinical and metabolic parameters such as liver enzymes, degree of hepatic steatosis, insulin resistance, lipid profile, and inflammatory markers will be evaluated compared to a control group. Additionally, by examining the relationships between these parameters and quality of life as well as dietary adherence, the potential therapeutic role of the DASH diet in the management of pediatric MASLD will be elucidated.

Inclusion Criteria:

• Eligibility criteria include being between 11 and 18 years of age,
• Having a body mass index (BMI) ≥95th percentile,
• Having hepatic steatosis detected by magnetic resonance imaging (MRI) and proton density fat fraction (PDFF) measurement (cutoff value ≥5%).

Exclusion Criteria:

• Other liver diseases (such as viral hepatitis, autoimmune hepatitis, Wilson's disease),
• Alcohol consumption,
• History of type I or type II diabetes,
• Use of medications that may affect fatty liver or blood lipid profile (corticosteroids, metformin, vitamin E, omega-3 fatty acids, etc.),
• Having participated in a weight loss program or undergone bariatric surgery prior to the study,
• Presence of chronic inflammatory disease, thyroid dysfunction (hyperthyroidism and hypothyroidism),
• Having received antibiotic treatment and used nutritional supplements in the last 3 months prior to the study,
• Having a psychiatric disorder that may affect adherence to the diet or the safety of exercise.

The study will present de-identified individual participant data collected during the trial, including demographic, anthropometric, dietary, and physical activity data, the study protocol, the statistical analysis plan, and the informed consent form.