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Comparing Obesity Rates

Comparing Obesity Rates

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Science Fair Project Description

This science fair project was conducted to find out the relation between obesity and race. The science fair project involved comparing the Body Mass Index (BMI) African-Americans and Caucasians.
Complexity level:9
Project cost ($):30
Time required:1 hour to prepare, 2 days for the science project experiment
Material availability:Easily found
Safety concerns:Basis safety requirements


There is a higher percentage of obese African-Americans students than Caucasian students, within the age band of 15 to 18 years..



Obesity happens when a person has so much fat in his body that his health is affected and his life expectancy is reduced. Among the health problems associated with obesity are hypertension, heart disease, diabetes and difficulty in breathing.

One of the simplest ways to determine if a person is obese is to calculate the Body Mass Index (BMI).

BMI = [weight (kg)]/ [height (m) x height (m)]

BMI less than 18.5 – underweight

BMI between 18.6 until 24.9 – normal

BMI between 24.9 until 29.9 – overweight

BMI more than 30.0 – obese

Obesity happens due to excessive consumption of food and too little exercise. Sometimes it can also be due to genetic factors or even a very low metabolic rate. This is the reason why sometimes people put on weight despite eating small amounts of food. Other reasons include eating too much, physical inactivity, eating out too often and excessive consumption of sweetened drinks/junkfood.

Scientific Terms

Hypertension, heart disease, diabetes, BMI


The materials required for this science fair project:
- 50 African-American boys aged between 15  and 18 years old
- 50 African-American girls aged between 15  and 18 years old
- 50 Caucasian boys aged between 15  and 18 years old
- 50 Caucasian girls aged between 15  and 18 years old
(for more reliable results, ensure that the participants live in the same city and attend the same school)
- A measuring tape
- A flat wall
- A weighing machine
- 1 roll of masking tape


1. For this science fair project, the independent variable is the racial type of the participating students – African-American or Caucasian. The dependent variable is  the BMI of the participant. This is determined by measuring each participant’s height and the weight to calculate his/her BMI. The constants (control variables) are the age of the participant and the number of participants for each group.

2. The measuring tape is fixed on the wall  with masking tape. The weighing machine is also placed close by  so that the weight of the participant can be  recorded immediately after checking the height.

3. The participants are separated into 4 groups as follows :

a. 50 African-American boys

b. 50 African-American girls

c. 50 Caucasian boys

d. 50 Caucasian girls

4. The height of each participant  is  measured in meters and their weight is measured in kilograms. Using the formulae provided above, the participants’ BMI is calculated.  The BMI value  will indicate  whether the participant is obese.

5. The number of obese participants  in each group is counted and recorded  in the table given below. The percentage of the obese persons  in each group is calculated and recorded in the table below.



In our experiment, it  was observed that there was a higher percentage of obese African-Americans than Caucasians. There was 38% obesity amongst African American boys and the 34% amongst African-American girls. In contract, there were 2% obese Caucasian boys 22% obese  Caucasian girls.

Race and Gender

Number of Obese

Under/Overweight, normal

Percent obese %

African-American - boy




African-American - girl




Caucasian - boy




Caucasian - girl




The chart below represents our findings.

obesity science fair project 0


The hypothesis that there is a higher percentage of obese African-Americans teenagers between ages 15 and 18, compared to  Caucasians of the same age, is proven to be true.

The main treatment for obesity is the control of food intake by dieting and burning of calories by exercising. This is normally supplemented with medication to reduceone’s appetite and decrease  the percentage of fat absorbed. Sometimes surgery is also performed to help a patient reduce weight.

Also consider

For more reliable results, we should conduct the survey across several schools as well as several towns/cities. The results for a particular school or even a particular town/city may deviate from the norm.

Compare the rate of obesity amongst Hispanic-Americans and African-Americans.

You could also compare the waistlines of the participants.


Obesity -

Obesity and overweight statistics -

Obesity -

Related videos

Hey there! Here are some awesome videos about this science project that we think you'll really like. They're not only super fun, but they'll also help you learn more about the science behind the project. So sit back, relax, and get ready to have some fun!!
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