In this chapter, we explore the mechanisms through which the nutritional status influences the aging process, focusing on key nutrient-sensing pathways such as insulin/IGF1 and TOR for glucose and amino acids, respectively. Additionally, we will discuss how this relates to the cellular energy state being monitored by SIRTs and AMPK. Insulin signaling involves the insulin receptor (INSR), insulin receptor substrate (IRS), and key signaling molecules like PI3K (phosphatidylinositol-4,5-bisphosphate 3-kinase), AKT (AKT murine thymoma viral oncogene homolog), and the transcription factor FOXO1 (forkhead box O1). We will examine how these pathways adjust to environmental stimuli and maintain equilibrium in cellular function. Caloric restriction, known to extend the lifespan in various model organisms like yeast, worms, and flies, operates through mechanisms that are similarly influential in humans, suggesting a universal strategy for extending life and combating age-associated diseases such as T2D, CVD, and cancer. Additionally, we will explore the interconnections between circadian rhythms and metabolism, highlighting their potential roles in enhancing healthspan and preventing age-related diseases. This discussion aims to provide insights into how dietary interventions can promote healthy aging by modulating these fundamental biological pathways.