Explain The Metabolic Response To Prolonged Starvation
The metabolic response to prolonged starvation
Early stage of prolonged starvation
Starvation occurs when the body has a severe lack of nutrients needed to survive. The body has ways of adapting to periods without food, for example overnight it needs to survive without any additional nutrients whilst asleep. The body however also has ways of adapting for as long as long as 5-6 weeks (Garber, 1974). Therefore, looking at the metabolic state during starvation is over a long time period.
The body uses glucose as its main energy source and there is only around 12g of free glucose circulating in the blood, this is depleted after around 2 hours. (Frayn, 2003) The period of fasting overnight is longer than 2 hours and so the body needs to get glucose from its stores in order to keep the blood glucose levels regulated. The body is able to use glycogen stores, glycerol from triacylglycerol, some amino acids and lactate to form glucose (Frayn, 2003). …show more content…
It is a time where the concentration of free glucose is low and the insulin/glucagon ratio has decreased, however free fatty acids (FFA) are high in concentration (Frayn, 2003). Glucose is the main source of energy for the brain and so the body turns to its glycogen stores as the body can rapidly hydrolyse them to form glucose in the process called hepatic glucogenolysis (Potthoff, 2009). The liver has the ability to convert glycogen to glucose which can then be transported to the brain more readily than skeletal muscles, where glycogen is also stored. The liver contains around 120g of glycogen which depletes within 18-24 hours. (Frayn,
Early stage of prolonged starvation
Starvation occurs when the body has a severe lack of nutrients needed to survive. The body has ways of adapting to periods without food, for example overnight it needs to survive without any additional nutrients whilst asleep. The body however also has ways of adapting for as long as long as 5-6 weeks (Garber, 1974). Therefore, looking at the metabolic state during starvation is over a long time period.
The body uses glucose as its main energy source and there is only around 12g of free glucose circulating in the blood, this is depleted after around 2 hours. (Frayn, 2003) The period of fasting overnight is longer than 2 hours and so the body needs to get glucose from its stores in order to keep the blood glucose levels regulated. The body is able to use glycogen stores, glycerol from triacylglycerol, some amino acids and lactate to form glucose (Frayn, 2003). …show more content…
It is a time where the concentration of free glucose is low and the insulin/glucagon ratio has decreased, however free fatty acids (FFA) are high in concentration (Frayn, 2003). Glucose is the main source of energy for the brain and so the body turns to its glycogen stores as the body can rapidly hydrolyse them to form glucose in the process called hepatic glucogenolysis (Potthoff, 2009). The liver has the ability to convert glycogen to glucose which can then be transported to the brain more readily than skeletal muscles, where glycogen is also stored. The liver contains around 120g of glycogen which depletes within 18-24 hours. (Frayn,