EXAMPLE 18 1 Weight Loss Through Diet If

EXAMPLE 18. 1 Weight Loss Through Diet If you ordinarily expend 2000 kcal/day and you go on a diet of 1500 kcal/day, about how long will it take to diet off 1. 0 lb of fat? Solution You will use 2000 – 1500 = 500 kcal/day more than you consume. There about 3500 kcal in 1. 0 lb of fat, and so it will take 1 day 3500 kcal x = 7 days 500 kcal (Keep in mind, however, that your weight loss will not be all fat. You will probably lose more than 1 lb, but it will be mostly water with some protein and a little glycogen. ) Exercise 18. 1 A A person who expends 1800 kcal/day goes on a diet of 1200 kcal/day without a change in activities. Estimate how much fat she will lose if she stays on this diet for three weeks. Exercise 18. 1 B A person who expends 2200 kcal/day goes on a diet of 1800 kcal/day and adds exercise activities that use 180 kcal/day. Estimate how much fat he will lose if he stays on this program for three weeks.

EXAMPLE 18. 2 Weight Loss Through Exercise A 135 -lb person doing high-impact aerobics burns off about 6. 9 kcal/min. How long would the person have to exercise to burn off 1. 0 lb of adipose (fat) tissue? Solution One pound of adipose tissue stores 3500 kcal of energy. To burn it off at 6. 9 kcal/min requires 3500 kcal x 1 min 6. 9 kcal = 500 min It takes about 500 min (more than 8 hr) to burn off 1 lb of fat, even doing high-impact aerobics. (However, you don’t have to do it all in one day. ) Exercise 18. 2 A Walking a mile burns off about 100 kcal. About how far do you have to walk to burn off 1. 0 lb of fat? Exercise 18. 2 B A moderately active person calculate the calories needed each day to maintain proper weight by multiplying the desired weight (in pounds) by 15 kcal/lb. How many calories per day do you need to maintain a weight of 150 lb?

EXAMPLE 18. 3 Body Mass Index What is the BMI for a person who is 6 ft 1 in. tall and weighs 205 lb? Solution The person’s height is (6 x 12) + 1 = 72 + 1 = 73 in. BMI = 705 x 205 73 x 73 = 27 The body mass index is 27. Exercise 18. 3 A What is the BMI for a person who is 5 ft tall and weights 120 lbs? Exercise 18. 3 B What is the maximum weight, in pounds, that a person 5 feet 10 inches tall can maintain and have a BMI that does not exceed 25. 0?