Prolonged fasting state to the point of starvation. A typical healthy 70-kg man
ID: 193275 • Letter: P
Question
Prolonged fasting state to the point of starvation.
A typical healthy 70-kg man has fuel reserves totalling about 670,000 kJ (see table). The energy need for a 24-hour period ranges from about 1600 kcal (6700 kJ) to 6000 kcal (25,000 kl), depending on the extent of activity. To answer the questions that follow show clearly all your calculations.
Fuel reserves in typical 70-kg man.
Available energy in k.J,
Organ Glucose or glycogen Triacylglycerol MobHizable proteins
Blood 250 200 0
Liver 1700 2,000 1,700
Brain 30 0 0
Muscle 5,000 2,000 100,000
a. How long does it take for the carbohydrate reserves to get exhausted?
b. How long does it take for the other stored fuels (mobilizable proteins and TG's) to get exhausted?
2. Prolonged fasting state to the point of starvation A typical healthy 70-kg man has fuel reserves totalling a bout 670,000 kJ (see table). The energy need for a 24-hour period ranges from about 1600 kcal (6700 k)_to 6000 kcal (25,000 kl), depending on the extent of activity. To answer the questions that follow show clearly all your calculations. Fuel reserves in typical 70-kg man Available energy in k.J Organ Blood Liver Brain Muscle Adipose tissue Glucose or glycogen Triacylglycerol MobHizable proteins 250 200 2,000 0 2,000 1700 1,700 30 0 5,000 100,000 330 170Explanation / Answer
Ans. #A. Total carbohydrate reserve in body = Sum of glucose and glycogen in all organs
= (250 + 1700 + 30 + 5000 + 330) kJ
= 7310 kJ
Given-
Energy consumption rate = 6700 kJ/ 24 hr (lowest) to 25000 kJ/hr (highest)
# Now,
Maximum time for energy supply =
Energy in carbohydrates / Lowest energy consumption rate
= 7310 kJ / (6700 kJ/ 24 hr)
= 26.19 hr
Minimum time for energy supply =
Energy in carbohydrates /Highest energy consumption rate
= 7310 kJ / (25000 kJ/ 24 hr)
= 7.02 hr
Therefore, the carbohydrate store is body can compensate energy demand for 7.02 – 26.19 hr depending on the extent of activity.
#B. Total mobilizable protein and Triacylglycerol reserve in body = Sum of mobilizable protein and Triacylglycerol in all organs
= (200 + 2000 + 2000 + 560000) kJ + (1700 + 100000 + 170) kJ
=666070 kJ
Given-
Energy consumption rate = 6700 kJ/ 24 hr (lowest) to 25000 kJ/hr (highest)
# Now,
Maximum time for energy supply =
Energy in MP & TG / Lowest energy consumption rate
= 666070 kJ / (6700 kJ/ 24 hr)
= 2385.92 hr = 99.41 days
Minimum time for energy supply =
Energy in carbohydrates /Highest energy consumption rate
= 666070 kJ / (25000 kJ/ 24 hr)
= 639.73 hr = 26.64 days
Therefore, the carbohydrate store is body can compensate energy demand for 639.73 – 2385.92 hr (i.e. 26.64 – 99.41 days) depending on the extent of activity.
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