Impacts of protein-energy restriction on hepatic metabolism: mechanisms, adaptations, and physiological consequences

Abstract

Objective: To analyze the impacts of protein-energy restriction (PER) on hepatic metabolism, describing the key molecular and physiological mechanisms involved. The aim is to understand how protein and energy deficiency influences hepatic homeostasis. Literature review: PER is commonly associated with forms of malnutrition such as kwashiorkor and marasmus, which significantly impact patients from low socioeconomic backgrounds. This condition impairs hepatic protein synthesis, lipid mobilization, and energy metabolism, leading to hepatic steatosis, mitochondrial dysfunction, and alterations in apolipoprotein production. Clinical effects vary by life stage: in children, PER impairs growth and increases mortality; in adults, it intensifies metabolic stress and muscle loss; and in the elderly, it is associated with insulin resistance and physiological frailty. Furthermore, PER is closely linked to intestinal dysbiosis and increased mucosal permeability, which promote hepatic inflammation. Final considerations: PER impairs hepatic functions, alters lipid and protein metabolism, and manifests distinct effects across the lifespan, underscoring the need for nutritional and therapeutic strategies aimed at managing its complications.