Abstract Body: Background and Aims: Low-calorie weight loss diets with different macronutrient compositions have shown to result in clinically meaningful long-term weight loss. We aimed to identify plasma metabolites that significantly changed over two years in an intervention trial of low-calorie weight-loss diets with varying amounts of fats, carbohydrates, and proteins, and to investigate which changes in plasma metabolites are linked to better long-term weight loss.
Materials and methods: The present study included participants who were randomly assigned to one of 4 diets in the POUNDS Lost trial. Untargeted plasma metabolomics was performed; changes in 856 metabolites across various metabolic pathways from baseline to the end of the two-year intervention were calculated in 533 participants.
Results: We observed 571 metabolites (67%) showing statistically significant changes (P-_FDR < 0.05) following the two-year diet intervention (Figure panel a). We also identified core metabolites that significantly changed across all diet groups as well as specific metabolites that changed only in each of the 4 diet groups (panel b). Of the significantly modified metabolites by diets, 239 were significantly associated with 2-year weight changes, while others were not linked to weight loss (panel c). When stratifying by diet group, we identified 230 metabolites related to weight loss in response to one of the 4 diet interventions, including 22 metabolites within the lactoyl amino acid pathways, which showed the strongest sub-pathway associations with weight changes over two years in all diet groups.
Conclusion: Our study identified core and specific metabolic pathways associated with changes in all or each of three macronutrients that contribute to better long-term weight loss.