Chapter 17, Problem 1P

Interpretation Introduction

(a) Interpretation:

The percentage of calories that has been consumed after having caffe mocha and a blueberry scone, should be calculated, considering that the recommended daily caloric intake represents the 100 %

Concept introduction:

Depending on the age, gender, and type of physical activities performed bya person, there is an amount of recommended daily caloric intake that hasbeen calculated from measuring the amount of energy used for basal metabolic functions, for digestion, and physical activity.

The fraction of calories consumed in a meal can be calculated as follows:

  $\text{F}=\frac{\text{Consumed calories}}{\text{Daily recommendeded}}\times 100\%$

Explanation of Solution

Using the information from the table shown in the website from the link provided in the question, for a woman that has age between 19 to 30 years, the recommended daily caloric intake should be 2,000 kilocalories, if the woman is sedentary. Considering that in food packaging calories is equal to kilocalories, we can say the coffee provides 260 kilocalories and blueberry scone provides 460 kilocalories, thus, total kilocalories will be 720. Calculate the percentage that 720 kilocalories represent in a total amount of 2,000 as follows:

  $\text{F}=\frac{\text{Consumed calories}}{\text{Daily recommendeded}}\times 100\%$

Putting the values,

  $\begin{array}{c}\text{F}=\frac{\text{720 kilocalories}}{\text{2000 kilocalories}}\times 100\%\\ =36\%\end{array}$

Therefore, percentage of consumed calories is 36%.

Interpretation Introduction

(b) Interpretation:

The calculated calories should be converted into kilojoules.

Concept introduction:

Depending on the age, gender, and type of physical activities performed by a person, there is an amount of recommended daily caloric intake that has been calculated from measuring the amount of energy used for basal metabolic functions, for digestion, and physical activity.

In 1 kilocalories there are 4.2 kilojoules. Therefore, $\left(\frac{4.2\text{ kilojoules}}{1\text{ kilocalories}}\right)$ is used as a conversion factor.

Explanation of Solution

Considering that 1 kilocalories = 4.2 kilojoules, the calculated calories can be converted into kilojoules:

  $\begin{array}{c}\text{C}=\text{720 kilocalories}\left(\frac{4.2\text{ kilojoules}}{1\text{ kilocalories}}\right)\\ =3024\text{ kilojoules}\end{array}$

Therefore, the calories consumed in breakfast are 3,024 kilojoules.