Question

Suppose an individual wants to lose 10 pounds (about 5 kg). The person’s weight has been

steady for over a year with well established eating and exercise patterns. In this problem,

you will model how different choices affect the weight loss.

(a) What can you infer about caloric intake versus caloric use for this person from the

problem statement?

(b) Suppose the person makes a few changes that result in consuming 10% fewer kilocalories

every day, going from 2,400 kcal/day to 2,160 kcal/day. With this change alone, how long

will it take for the person to lose the weight assuming all other activities remain the same?

(c) Instead of just changing diet, the person also adds an exercise routine. This routine

increases the caloric requirements by 86 kcal/day. (This is approximately equivalent to

taking a brisk 30 minute walk 4 days a week). Assuming there is no change in the body’s

structure (no muscle mass is added), how long will it take for the person to lose the weight?

(d) If 1 kg of body fat is replaced by 1 kg of skeletal muscle the person’s weight will not

change. However, the daily caloric needs will. According to Tables 2.1 and 2.3 in your text,

how much energy has to be used to lose the 1 kg of body fat, and how much do daily caloric

needs increase by adding the 1 kg of skeletal muscle?

(e) Comment on the effectiveness of the various approaches.

Answer 1

a. Since the weight of the person has been stead for an year, it infers that his caloric intake and consumption has been equal. In order to lose weight, the individual has to reduce his caloric intake so that the body can tap into his fat reserves so that he can lose weight.

b. To lose 10 pounds, 35000 KCal needs to be eliminated from the body. If the person reduces 240 Kcal each day from their diet, it would take 146 days to lose 10 pounds.

c. Inclusive of reducing calories, an 86 KCal deficit would sum upto 328 KCal. At this rate, it would take 107 days to lose weight.

d. Data from the tables not available to calculate.

e. Data from the tables not available for inference.