Final answer:
In extreme starvation, the body catabolizes muscle tissue to produce glucose, leading to muscle wasting and potentially causing edema in conditions like kwashiorkor.
Step-by-step explanation:
Starvation and Muscle Wasting
In extreme starvation, when the body is deprived of nutrition for an extended period, it enters a survival mode prioritizing fuel for the brain and conserving proteins. Initially, the body turns to gluconeogenesis to produce glucose, but if glycogen stores are depleted, it will begin to convert muscle tissue to glucose. This muscle wasting leads to the spindly appearance of limbs, and eventually may cause edema in conditions like kwashiorkor, which is related to severe undernutrition.
During starvation, ketosis occurs when the body uses fat reserves to produce ketone bodies, providing an alternate energy source for the brain and other organs. However, when these reserves are emptied, the body has no choice but to catabolize its own proteins from muscle tissue, exacerbating muscle wasting and contributing to edema.