Association between dietary amino acid intake and the risk of metabolic dysfunction-associated steatotic liver disease

• Dietary intake of amino acids is positively associated with the risk of MASLD. • Dietary intake of lysine is specifically linked to a higher risk of MASLD. • Dietary intake of lysine is also associated with severe MASLD. • Three amino acid intake patterns were identified, with the ’Lysine-Methionine’ pattern being associated with a higher risk of MASLD. • Red meats are prominent examples of the ’Lysine-Methionine’ pattern. Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) is becoming the major chronic liver disease, and diet plays crucial role in MASLD prevention. The study aimed to explore the association between dietary amino acids with MASLD risk. Utilizing data from the U.S. NHANES (2017–2020) and UK Biobank (2006–2010), we investigated the association between dietary intake of combined or specific amino acids, and the risk of MASLD, severe MASLD and MASLD-related events. And we identified MASLD-risk amino acid intake patterns and their primary food sources. The study included 5,568 participants from the U.S. NHANES and 48,261 from the UK Biobank, with MASLD prevalence of 34.3 % and 28.4 %, respectively. In QGC model, each quartile increase in combined amino acid intake was associated with a higher MASLD risk in the U.S. NHANES (aOR = 1.17, 95 % CI: 1.01–1.37, P = 0.035) and UK Biobank (aOR = 1.07, 95 % CI: 1.002–1.15, P = 0.042). Increased lysine intake was particularly linked to elevated MASLD risk in U.S. NHANES (aOR = 1.49, 95 % CI: 1.08–2.05, P = 0.023) and UK Biobank (aOR = 1.12, 95 % CI: 1.01–1.24, P = 0.032). Substituting lysine with other amino acids was associated with reduced MASLD risk. Lysine intake was also associated with a higher risk of severe MASLD (aHR = 1.13, 95 % CI: 1.04–1.23, P = 0.002) but not liver cirrhosis or HCC. The ‘Lys-Met’ pattern was identified as a MASLD-risk pattern, with red meats being a representative food source. Lysine plays a major role in the association between amino acid intake and risk of MASLD. Dietary patterns rich in lysine, such as red meat, could be key targets for MASLD prevention strategies.