Protein Intake Across the Lifespan: Optimizing Health, Function, and Longevity.

Abstract

Lifestyle Medicine leverages evidence-based health behaviors: nutrition, physical activity, restorative sleep, stress management, social connection, and avoidance of risky substances to prevent, treat, and often reverse chronic disease. Nutrition is underutilized in routine care. A growing body of evidence demonstrates that a whole-food, plant-predominant diet (WFPD) confers broad benefits across cardiometabolic, reproductive, and mental health domains. Mechanistic and clinical studies link WFPDs to reduced risk of cardiovascular disease, diabetes, cancer, and depression through improved microbiome diversity, increased short-chain fatty acid production, reduced oxidative stress and inflammation, and enhanced insulin sensitivity. Beyond disease prevention, plant-forward diets improve psychological well-being via nutrient pathways that modulate neurotransmitter synthesis and the gut-brain axis. Some patients can benefit from protein intakes above the Recommended Daily Allowance (RDA) of 0.8g/kg/day for adults in a variety of settings. Well-planned plant-based diets can achieve significantly higher levels of protein intake, achieved through diverse sources such as legumes, soy, grains, nuts, and seeds. Adequate and well-distributed protein supports fertility, fetal growth, lactation, and preservation of lean mass through perimenopause and aging. Implementing WFPDs with individualized protein guidance can extend health span, enhance functional independence, and reduce medication dependence, reaffirming wholesome food as a cornerstone of modern medicine.