A large UK Biobank analysis of 51,717 participants found that combining recommended physical activity levels with higher omega-6 polyunsaturated fatty acid concentrations reduced metabolic dysfunction-associated steatotic liver disease (MASLD) risk by 71% over nearly 8 years. The protective effect peaked at 189 minutes of moderate-vigorous activity weekly, with omega-6 fatty acids showing independent liver benefits while omega-3s showed no significant association. This challenges conventional wisdom that typically emphasizes omega-3 over omega-6 fatty acids for health benefits. The finding suggests liver health depends on both behavioral interventions like exercise and specific metabolic factors including fatty acid profiles. However, this represents observational data that cannot establish causation, and the UK population may not reflect global diversity in diet and genetics. As a preprint awaiting peer review, these results require validation before clinical recommendations change. The research adds nuance to fatty acid recommendations and reinforces that liver disease prevention likely requires multifaceted approaches combining lifestyle and nutritional strategies rather than single interventions.