Dietary total, animal, and plant protein-energy ratio and risk of mortality: results from the NHANES III and an all life-long animal experiment

The study examined the relationship between total, animal, and plant protein-energy ratio and their combinations with mortality through Cox regression models, restricted cubic spline (RCS) analysis, and isocaloric (2.5%, 5%, and 10%) substitution analysis. In the animal experiment, 60 male Wistar rats were randomly assigned to normal protein diets (NC=10) or isocaloric-restricted high-protein diets (HP=50) for 101 weeks. Subsequently, renal histologic staining was performed using hematoxylin and eosin, and serum amino acid levels were measured through targeted metabolomics. Changes in hepatic gene expression profiles were assessed via principal component analysis (PCA), analyzed using protein interaction networks and modules with the STRING online database, and validated through quantitative real-time PCR (qPCR).