Question

Exercises Use R for all calculations unless otherwise specified. Refer to the Body Fat data we used in Lecture 13. We ultimately want to be able to predict body fat using the other m.

Answer 1

To metabolize 0.500 kg of fat, 4.65 kcal are supplied. The kcal/min required to metabolize fat at this rate is 0.155 kcal/min. The claim that a person can metabolize 0.500 kg of fat in 2.00 h by exercising vigorously is unreasonable due to the high rate of energy utilization required.

Step-by-step explanation:

The question is related to calculating the calories supplied by metabolizing fat, the kcal/min required to metabolize fat, and identifying any unreasonable results. In order to answer these questions, we need to know that body fat supplies 9.30 kcal/g when dietary intake is less than needed to fuel metabolism.

1. (a) To calculate the kcal supplied by metabolizing 0.500 kg of fat, we multiply the mass (0.500 kg) by the energy content (9.30 kcal/g). This gives us 4.65 kcal.
2. (b) To calculate the kcal/min required to metabolize fat at the rate of 0.500 kg in 2.00 h, we divide the energy content (4.65 kcal) by the time in hours (2.00 h), then convert to minutes. This gives us 0.155 kcal/min.
3. (c) The result that a person can metabolize 0.500 kg of fat in 2.00 h by vigorously exercising seems unreasonable because it would require a very high rate of energy utilization, which is unlikely to be sustainable.
4. (d) The premise that a person can lose 0.500 kg of fat per day by vigorously exercising for 2.00 h per day is unreasonable because it would require an unsustainable level of energy expenditure.