Question

Calculate the BMI of a woman who is 5 feet, 3 inches tall and weighs 130 pounds, and of a man who is 5 feet, 10 inches tall and weighs 215 pounds. State whether either of these people could be classified as "overweight" or "obese." Please refer to figure \(19.12\) to answer the following questions:

Short answer

The woman's BMI is 22.97, placing her in the normal weight range (18.5 to 24.9). The man's BMI is 30.84, classifying him as obese (BMI ≥ 30). Therefore, the woman is neither overweight nor obese, while the man is considered obese.

Step-by-step solution

Convert height and weight to metric units

We need to convert the height from feet and inches to meters and the weight from pounds to kilograms. 1 foot = 0.3048 meters 1 inch = 0.0254 meters 1 pound = 0.453592 kg Woman's height: 5 feet 3 inches 5 feet = 5 * 0.3048 = 1.524 meters 3 inches = 3 * 0.0254 = 0.0762 meters Total height = 1.524 + 0.0762 = 1.6002 meters Woman's weight: 130 pounds 130 pounds = 130 * 0.453592 = 58.967 kg Man's height: 5 feet 10 inches 5 feet = 5 * 0.3048 = 1.524 meters 10 inches = 10 * 0.0254 = 0.254 meters Total height = 1.524 + 0.254 = 1.778 meters Man's weight: 215 pounds 215 pounds = 215 * 0.453592 = 97.521 kg

Calculate BMI for each person

Use the BMI formula to calculate the BMI of each person. Woman's BMI = \( \frac{58.967}{1.6002^2} \) = 22.97 Man's BMI = \( \frac{97.521}{1.778^2} \) = 30.84

Classify BMI for each person

Classify each person's BMI using the following ranges: - Underweight: BMI < 18.5 - Normal weight: 18.5 ≤ BMI < 24.9 - Overweight: 24.9 ≤ BMI < 29.9 - Obese: BMI ≥ 30 Woman's BMI is 22.97, which falls within the normal weight range (18.5 to 24.9). Man's BMI is 30.84, which falls within the obese range (BMI ≥ 30).

Determine if either person is overweight or obese

Based on the calculated BMI values: - The woman is not overweight or obese, as her BMI is within the normal weight range. - The man is classified as obese, as his BMI is greater than or equal to 30.

Key concepts

Body Mass Index

The Body Mass Index (BMI) is a numerical value of your weight in relation to your height. It's a standard screening tool used to categorize individuals based on their body size as underweight, normal weight, overweight, or obese. To calculate BMI, you need to use the formula:
\[\[\begin{align*}BMI =\frac{weight \, in \, kilograms}{(height \, in \, meters)^2}\end{align*}\]\]
This equation makes it possible to evaluate whether a person has an appropriate body weight for their height. It's worth mentioning that BMI doesn't directly measure body fat, so it isn't a definitive diagnostic tool for determining someone's health status, but it does provide a quick assessment of weight-related health risk.

Weight-to-Height Ratio

The weight-to-height ratio, expressed through BMI, gives us a simple way to understand the balance between someone's weight and their height. Maintaining a proper weight-to-height ratio is essential for health, as deviations could indicate potential health risks such as malnutrition or obesity. The concept behind this ratio is to assess how a person's body mass is distributed and to encourage a balance that is appropriate for their height.

Health Assessment

BMI is commonly used for health assessments as it helps in identifying potential health risks that come with different weight statuses. For example, a higher BMI can indicate a higher risk of health problems like heart disease, type 2 diabetes, and certain cancers. Similarly, a lower BMI may point to malnutrition, anemia, or osteoporosis. It's crucial to note, however, that BMI should be considered alongside other assessments and tests to provide a more comprehensive health evaluation, as it does not consider factors like muscle mass, bone density, overall body composition, and racial and sex differences.

Metric Unit Conversion

In many countries, including the United States, people commonly measure their height in feet and inches and their weight in pounds. However, BMI calculations require metric units: meters for height and kilograms for weight. To facilitate this, one must convert these units:

• 1 foot = 0.3048 meters,
• 1 inch = 0.0254 meters,
• 1 pound = 0.453592 kilograms.

Understanding these conversions is crucial in accurately determining your BMI. Metric units facilitate international comparisons and scientific research, providing a standardized method for health professionals to communicate.