During long periods of starvation, fats or adipose tissues are used as a main source of energy. Which of the following is not true about it?
**Core Concept:** In cases of severe calorie deficiency, the body's primary response is to break down stored fats, primarily from adipose tissues, for energy production.
**Why the Correct Answer is Right:** When the body experiences prolonged starvation or insufficient food intake, the liver starts converting stored fats (triglycerides) into fatty acids and glycerol. These components are then used to produce energy through a process called ketogenesis, which results in the production of ketone bodies such as beta-hydroxybutyrate (BHB) and acetoacetate. This process, known as ketosis, helps maintain vital functions like brain activity and prevents the depletion of glycogen stores in the liver and muscles.
**Why Each Wrong Option is Incorrect:**
A. This option could be incorrect because the liver can adapt to produce ketone bodies from fats during starvation, providing an alternative energy source for the body.
B. Although the liver plays a crucial role in ketogenesis, it is not the only organ involved. Other tissues, such as adipose tissue and muscle, also contribute to ketone body production.
C. Inaccurate because the body continues to utilize glucose from glycogen stores even in ketosis, as glucose is essential for the brain to function properly.
D. Incorrect because the liver does not exclusively rely on glucose for energy during starvation; it can also utilize ketone bodies derived from fats.
**Clinical Pearl:** Maintaining a healthy diet and preventing prolonged starvation is crucial for overall health and to avoid negative physiological consequences like ketonuria and ketonemia, which can lead to ketoacidosis and neurological impairment.
**Correct Answer:** C. During long-term starvation, the liver does not solely rely on glucose for energy; it can also utilize ketone bodies derived from fats.
**Core Concept:** During prolonged starvation, the body adjusts its energy production by shifting from glucose (glycolysis) to ketone bodies (beta-oxidation) as the primary energy source. The liver plays a crucial role in converting fats into ketone bodies, serving as an alternative fuel source during times of insufficient glucose availability.