University college of Northern denmark (UCN)

Fasting and stress metabolism represent adaptive physiological responses that preserve vital organ function during periods of energy deprivation or increased demand. In fasting states, the body shifts from exogenous glucose utilization to endogenous energy production through glycogenolysis, gluconeogenesis, and lipolysis. During stress, counter-regulatory hormones such as cortisol, glucagon, and catecholamines increase substrate availability to support the brain and muscles.

Digestion is a complex, integrated physiological process in which food is mechanically and chemically broken down into absorbable nutrients. Through coordinated actions of the gastrointestinal tract, digestive enzymes, bile, and peristalsis, macronutrients are converted into bioavailable substrates essential for energy production, cellular repair, and metabolic regulation. Impairments in digestion or absorption can rapidly affect nutritional status, immune competence, and overall homeostasis, hi...

The liver and gallbladder play a central role in metabolic regulation, detoxification, and digestion. The liver functions as a biochemical hub, responsible for nutrient metabolism, glycogen storage, protein synthesis, and the neutralization of endogenous and exogenous toxins. The gallbladder complements this process by storing and concentrating bile, which is released in response to dietary fat to facilitate lipid digestion and absorption.

Energy and Nutrients – Lecture Summary | Comprehensive Overview of Metabolism, Macronutrients, and Micronutrients

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