Fig. 1: Correlation between chronological age and metabolic age for the test set of the 1D 1H NOESY-based model.

(A, blue) The cross-validation sets of the model based on quantified metabolites and clinical parameters (B, red), and the corresponding independent test set (C, green). The NOESY-based model achieved a Pearson correlation coefficient of 0.92 on the test set, with more than 75% of individuals exhibiting prediction errors smaller than 10 years. Slightly lower performance was observed for the metabolite-based model in both cross-validation (R = 0.87) and test evaluations (R = 0.88).