Metabolic dysfunction-associated steatotic liver disease (MASLD) is the leading cause of chronic liver disease worldwide, affecting one in three individuals. As MASLD pathogenesis closely relates to that of obesity and insulin resistance, lifestyle intervention remains the treatment foundation of MASLD, alone or in combination with pharmacological interventions to prevent progression to steatohepatitis and liver fibrosis. In this chapter, the role of lifestyle interventions, including nutrition, physical activity, avoidance of alcohol and nicotine, and the role of dietary supplementation in MASLD is reviewed. Common barriers to lifestyle interventions, current clinical practice guidelines, and research gaps in the field are also reviewed.