# 16.2: Global Distribution of BMI

• Joylin Namie
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### Global Distribution of BMI

Format: In-person or online

Body Mass Index categories

Author: Nelson, Katie

Time needed: 40-60 minutes

#### Learning Objectives

• Chart and analyze global BMI data.
• Identify trends in global BMI data.
• Calculate one’s own BMI and relate it to larger global and national trends.

#### Supplies Needed

• Scale and measuring tape
• Worksheet (provided)
• Graphing software or PowerPoint

#### Introduction

In this activity, students use global Body Mass Index (BMI) data compiled by the World Health Organization (WHO) to create a chart that represents the average (mean) BMI for multiple countries from 1975 to 2015. Students also calculate their own BMI and relate it to larger global and national trends.This activity prompts students to reflect on the relationship between one’s environment and biology in determining health.

#### Steps

1. Students will weigh themselves and measure their height, documenting these data in pounds and feet/inches.
2. Using the National Institute of Health BMI calculator, students calculate their own BMI.
3. Students select six countries to track. They then access these countries, using WHO data and list the percentage of each country’s population that have a BMI of 30 or greater by year.
4. Using a charting software or PowerPoint chart feature, students input the BMI data from all of their six countries into a single chart, including data from 1975, 1985, 1995, 2005, 2015. They then project what the BMI will be for each country in 2025.
5. Students analyze the data, discuss trends, and hypothesize why there are differences between countries and changes over time.
6. Students reflect on their own BMI in relation to country trends.

#### Review Questions

• Why do BMI differ so much from country to country?
• What could be the causes of the progressive increase in BMI in most countries since 1975?
• Who benefits from the global obesity epidemic? Think about the following industries and institutions: How might the medical establishment profit from obesity? The fitness industry? The diet industry? Fashion? Pharmaceutical companies? Food manufacturers? Advertisers?

#### Tips and Suggestions

Some students may be uncomfortable disclosing their weight and height. If this is the case, you may wish to modify this activity. One way to do so is to allow students to omit their own raw BMI data and instead only answer the questions in which they reflect on their BMI as it compares to national data and in general, rather than specific, terms.

If this is an in-person lab, rank how adaptable to online learning it would be(mark in bold):

## References

Namie, Joylin. 2019. “Chapter 16: Contemporary Topics: Human Biology and Health.” In Explorations: An Open Invitation to Biological Anthropology, edited by Beth Shook, Katie Nelson, Kelsie Aguilera, and Lara Braff. Arlington, VA: American Anthropological Association. http://explorations.americananthro.org/

World Health Organization (WHO). 2017b. “Obesity and Overweight.” Fact Sheet. Last modified October 2017. http://www.who.int/mediacentre/factsheets/fs311/en/.

Women Body Mass Index by unknown is in the public domain.

### Global Distribution of BMI Worksheet

According to the World Health Organization (WHO), more than two billion people throughout the world are overweight or obese, which is defined as having a body mass index (BMI) over 30. As Joylin Namie notes in chapter 16, “for the first time in human history, most of the world’s population lives in countries where overweight and obesity kill more people than hunger does.” Of course, the causes for these growing rates of obesity are as complex as the problems obesity causes. Some causes include a sedentary lifestyle, overeating and eating processed and calorie dense foods. In this activity, you will access data from the WHO on BMI percentages and track changes in BMI over time in six countries.

#### Step One: Calculate Your BMI

Using a scale and measuring tape, weight yourself and measure your height. Document your personal data on a note card or scrap of paper. If you wish, you may include your data below, however this is not required if you are not comfortable disclosing this information. Be sure to indicate standard or metric measurements.

Weight _____________ pounds / kilograms

Height _____________ feet & inches / centimeters

Now, navigate to the National Institute of Health’s online BMI calculator. Input your height and weight data into the calculator and document your BMI score in the space below. You can also calculate your BMI using this chart.

Total BMI____________

Which category does your BMI fall into (see chart below)? _______________________

 BMI Category <18.5 Underweight 18.5–24.9 Normal weight 25–29.9 Overweight 30 or greater Obesity

#### Step Two: Document Global BMI Data

Navigate to the WHO’s interactive global obesity atlas and select six countries you wish to document. Type the names of each country into the country heading in the table below. Then, within the atlas, click on the “view by sex/year” lab at the top left, select “Both sexes”, scroll down to 1975 and click on that year. This will display the average (mean) BMI for each country in 1975. Using your computer mouse, hover the arrow over each of the countries you have selected and then type in the percentage for each country. Continue this process for each year in the chart and for each country.

#### BMI Data for Select Countries

 Country 1 Country 2 Country 3 Country 4 Country 5 Country 6 1975 1985 1995 2005 2015

#### Step Three: Graph the Data

Next, using a graphing software or the graphing feature in google docs or PowerPoint, create a line graph with all six countries. In addition to data points for 1975, 1985, 1995, 2005 and 2015, add a space on the graph for 2025 (but with no data). Be sure the names of the countries and the data points (numbers) are labeled and clear. Your graph will look something like the one below, except with six data sets, not three. Give your chart a title and copy and paste it in the space below the example chart.

Line graphing tutorials:

• For a tutorial on how to create a line graph in Microsoft PowerPoint, click here.

#### Example Chart

Paste your chart in the space below.

### Step Four: Analyze the Data

Study the chart you created carefully and make an educated guess what the average BMI will be for the countries in your chart for the year 2025. Add these numbers to the table below. Don’t forget to change the country names to the ones in your data sets. Then, answer the questions below.

## BMI Estimate for 2025

 Country 1 Country 2 Country 3 Country 4 Country 5 Country 6 2025
1. What happened to the BMI data in your chart from 1975 to 2015? Was it the same for all countries in your chart?
2. Based on what you learned in chapter 16, explain why you think the trends you noted in your chart occurred. What accounts for the similarities or differences between the countries?
3. What do you think are the global consequences for all humans of these trends?

#### Step Five: Wrap-up

Return to the WHO interactive atlas and locate the most recent BMI percentage for the country where you currently live. Then answer the questions below.

1. How does your BMI (from Step 1) compare with the most recent average for your country? Why do you think your BMI is the same or different from the average?
2. If you lived in a different country, one with a different average BMI, do you think over time your BMI would become similar to that country’s average? Explain.
3. Which do you think more strongly influences your own health, your environment or your inherited biology? Explain.

This page titled 16.2: Global Distribution of BMI is shared under a CC BY-NC 4.0 license and was authored, remixed, and/or curated by Joylin Namie via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.