Thoughts on dietary interventions for metabolic syndrome (MetS) in an era of metabolic heterogeneity

Metabolic syndrome (MetS) has long been used as a pragmatic tool for population-level cardiometabolic risk stratification, rather than as a mechanistically defined disease entity. However, mounting evidence suggests the existence of marked biological heterogeneity among individuals meeting identical MetS criteria, encompassing diverse metabolic phenotypes, disease trajectories, and responses to interventions. Such heterogeneity helps explain the limited and inconsistent effectiveness of uniform dietary strategies. In parallel, dietary research has shifted from a nutrient-centric approach to a food-based dietary pattern, emphasizing higher intakes of whole foods and reduced consumption of ultra-processed foods. In the context of metabolic heterogeneity, these shared food-level characteristics may confer relatively consistent metabolic benefits across diverse phenotypes. Future research may shift from uniform dietary recommendations to stratified strategies, grounded in dietary principles and informed by mechanistic insights, to better address metabolic heterogeneity.