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You Are What You Eat!

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Thinking about improving your sports performance? Want to help friends and family make the most of their physical fitness activities? One factor to consider is food! Whether you realize it or not, what you eat does change your body! It affects how you feel, and can even change how you perform in sports. This science fair project will help you explore the link between what goes in your mouth and what your legs and arms can do.


Areas of Science
Time Required
Very Long (1+ months)
This science fair project requires you to either have basic knowledge of good nutrition or be willing to spend some time learning about good nutrition. You will also need to collect parental permission from all people participating in this science fair project before beginning.
Material Availability
Readily available
Very Low (under $20)
Adult supervision is required.

Created by the following Schering-Plough employees: Jamie Furneisen, Maria-Christina Malinao, and Sheela Mohan-Peterson

Edited by Sandra Slutz, PhD, and Teisha Rowland, PhD, Science Buddies


Determine if healthy eating has an effect on physical fitness.


How does Michael Phelps swim so fast? How does David Beckham bend those kicks? How do Venus and Serena Williams keep winning tennis tournaments? Training and determination are big parts of their success, but eating right also plays an important part in their performances.

It is very important to have a balance of foods from the five different food groups every day. What are the five food groups? They are: grains, vegetables, fruits, dairy (like milk or yogurt), and proteins (found in fish, poultry, beans, nuts, red meat, and cheese). It is even more important to know how much of each food type you should eat, especially when you are going to spend a lot of energy playing sports. For example, making about 30% of your plate vegetables is healthy, but it is important to avoid eating lots of fats or sugars. So smothering your vegetables in a fatty cream sauce might not be a good idea! For more information about what makes a balanced diet, take a look at the healthy eating poster in Figure 1, below, from MyPlate.gov and the references in the Bibliography, below. In general terms, it is recommended to eat a balanced amount of the five different food groups every day to have a balanced diet.

The recommended ratios of five food groups are displayed on a plate and cup, fruits, grains, vegetables, protein and dairy
Figure 1. Each of the five different food groups are represented in this nutrition guide, with four groups represented on the plate and the fifth group (dairy) represented in the cup. The amount of space that each food group takes up on the plate or in the cup indicates how much of that food group you should eat compared to the other food groups. MyPlate was created by the United States Department of Agriculture (USDA) in 2011. (ChooseMyPlate.gov, 2011)

Good nutrition is not just about what foods you eat, it is also about when and how you eat them. We are all told that breakfast is the most important meal of the day. This is especially true for young athletes. Eating the right foods, first thing in the morning, will give you energy for sports; school; and a fun, full, and busy day. Lunch helps re-energize you for the afternoon, and dinner helps your muscles recover from all of your activities. Healthy snacks in between breakfast and lunch, as well as between lunch and dinner, will keep your energy level high to help you succeed.

In this science fair project, you will explore the connection between eating healthy foods and improving sports performance. You and a group of friends will form two test groups. Both groups will measure their physical fitness at the beginning of the experiment. Then the first group will try to eat as healthily as possible and follow the food pyramid recommendations, while the second group will continue to eat their normal diet. After four weeks, both groups will measure their physical fitness again. Do you think eating healthily will change the physical fitness levels of the people in the first group? What will happen to group number two's fitness levels? Get ready to find out if picking the right foods and the right amounts of each food can help you become a better athlete. Maybe one day we will see you with an Olympic gold medal around your neck!

Terms and Concepts



These websites contain more information about what qualifies as good nutrition:

To do this science fair project, your volunteers will need to keep track of what they eat. The USDA "SuperTracker" tool for which this project was originally written has been discontinued, but there are many third-party apps and websites you can use:

You can use these resources as nutritional guidelines for doing this science project:

  • United States Department of Agriculture. (n.d.). Food Group Gallery. MyPlate.gov. Retrieved November 10, 2023.
  • United States Department of Agriculture. (n.d.). Prepare Healthy Meals. MyPlate.gov. Retrieved November 10, 2023.

For help creating graphs, try this website:

  • National Center for Education Statistics, (n.d.). Create a Graph. Retrieved June 25, 2020.

Materials and Equipment

Experimental Procedure

Working with Human Test Subjects

There are special considerations when designing an experiment involving human subjects. Fairs affiliated with Regeneron International Science and Engineering Fair (ISEF) often require an Informed Consent Form (permission sheet) for every participant who is questioned. Consult the rules and regulations of the science fair that you are entering, prior to performing experiments or surveys. Please refer to the Science Buddies documents Projects Involving Human Subjects and Scientific Review Committee for additional important requirements. If you are working with minors, you must get advance permission from the children's parents or guardians (and teachers if you are performing the test while they are in school) to make sure that it is all right for the children to participate in the science fair project. Here are suggested guidelines for obtaining permission for working with minors:

  1. Write a clear description of your science fair project, what you are studying, and what you hope to learn. Include how the child will be tested. Include a paragraph where you get a parent's or guardian's and/or teacher's signature.
  2. Print out as many copies as you need for each child you will be surveying.
  3. Pass out the permission sheet to the children or to the teachers of the children to give to the parents. You must have permission for all the children in order to be able to use them as test subjects.

Gathering the Data

  1. To start this science fair project, you will need to find a group of volunteers, and their parents, who are willing to take part in the experiments.
    1. You will need at least 6 people, including yourself, but more is better. An even number of volunteers works best. The volunteers' parents should not be included in this number.
    2. All the volunteers should be about your age.
  2. Divide the volunteers into two even groups, called Group 1 and Group 2.
  3. Group 1 will be trying to eat healthily and will follow the recommendations from the healthy eating poster shown in Figure 1 in the Background from MyPlate.gov. The following resources can be used as nutritional guidelines for using the poster and doing this science project:
    1. MyPlate.gov's resource Food Group Gallery
    2. MyPlate.gov's resource Prepare Healthy Meals
  4. Group 2 will continue to eat their normal diet.
  5. Make sure each volunteer has permission from his or her parents to take part in the science fair project. With the help of a teacher or other adult, create a permission slip (also called a consent form). The permission slip should briefly describe this science fair project and should be signed by the parent(s) of each volunteer participating in the project.
    1. Consent forms are always required for projects where human subjects take part in an experiment.
    2. Because you will be gathering personal data from other people (their daily food intake and sports scores), your local science fair may want you to get pre-approval from the fair before starting your project. Consult this guide on Projects Involving Human Subjects for more details, or contact the people in charge of the science fair you are entering.
  6. Pick five physical activities that you can use to measure the athletic progress of each volunteer. You can pick any physical activity that can be timed or quantified in some way. Some possible activities include:
    1. Number of sit-ups done in 1 minute
    2. Number of jumping jacks done in 1 minute
    3. Number of push-ups done in 1 minute
    4. Time it takes to run the 50-yard dash
    5. Time it takes to run the 100-yard dash
    6. Time it takes to run a half mile
  7. On the first day of your experiment, measure the physical fitness level of each volunteer on all five of the physical activities. Be sure to give them a break between each activity. Record their results in a data table, like Table 1 below, in your lab notebook.

    Volunteer Group
    (#1 or #2)
    # of Sit-ups Done in 1 Minute # of Jumping Jacks Done in 1 Minute # of Push-ups Done in 1 Minute Time It Takes to Run 50-yard Dash Time It Takes to Run a Half Mile
    First Day Last Day First Day Last Day First Day Last Day First Day Last Day First Day Last Day

    Table 1. This is an example of what the physical fitness data table should look like. You can use any five quantifiable physical activities you choose. Make sure to fill in each volunteer's data on both the first and last day of the experiment.

  8. Every day for the next four weeks, have each volunteer (in both groups) keep track of how healthily they are eating by entering the food they ate using a food tracking website or app (see Bibliography). The procedure steps below were originally written for the SuperTracker app, which has been discontinued by the USDA, but you can follow a similar procedure with another website or app.
    1. To create a personal food log, each volunteer will need to create a profile and register with the website.
      • During registration, each volunteer will need to enter his or her approximate weight and height. Use the scale and tape measure to determine these measurements.
    2. Once registered, each volunteer should use the "Food Tracker" menu option from the "Track Food & Activity" tab at the top to keep track of the foods he or she has eaten that day.
    3. After entering all the foods eaten on a particular day, each volunteer should check the graph on the right that has "Total Percentage of Target" labeled on the bottom of it, along the x-axis. Each volunteer should see whether they are close to the "100% of target" for each of the five food groups listed. Specifically, each volunteer should see whether they are within 25% of the target range. If they are within 25% of the target for a given food group, they should score 1 point for that food group.
      1. For each of the five food groups, each volunteer should see if they are between 75% and 125% of the target. If they are, this means they are within 25% of the target (which is marked as 100%). For each food group that they are within 25% of the target, give the volunteer 1 point.
      2. For each of the five food groups, if a volunteer is less than 75% of the target, or more than 125% of the target, then they are not within 25% of the target. For each food group that they are not within 25% of the target, give the volunteer 0 points.
      3. Each volunteer should fill out a data table, like Table 2 below, for every day of the experiment, showing how healthy his or her diet was. In the end, they should add up all the points to calculate their "daily dietary score." The higher the daily dietary score, the healthier they ate that day. A perfect score for one day would be a 5, since this means they would have been within 25% of the target for each of the five food groups.
      4. Note: You may want to provide each of your volunteers with a pre-made data table for them to fill out.
      5. Note: Nutrition is a complex subject. It is not necessary for doing this science project, but to improve your understanding of the subject you may want to look into other dietary factors, such as cholesterol, sodium, portion size, calories, daily calorie limits, carbohydrates, and oils.

    Volunteer's Name: __________________     Volunteer's Group (#1 or #2): ________
    Dietary Guideline
    Recommendations for:
    Daily Score
    Day 1Day 2Day 3Day 4 Day 5Day 6
    Dairy (Milk & Yogurt)      
    Protein (Meats & Beans)      
    Daily Dietary Score
    (add together all points above):

    Table 2. Each volunteer should fill in a diet data table, like this one, for every day of the experiment. For each food group that they are within 25% of the target for that day, the volunteer scores 1 point. For each food group that they are not within 25% of the target for that day, the volunteer scores 0 points.

  9. Volunteers in Group 1 should try to maximize their daily dietary score by eating as healthily as possible. Volunteers in Group 2 can continue to eat their normal diet. Both groups should track their daily diet every day, as described in step 8, for 4 weeks.
  10. At the end of week four, re-test the physical fitness level of each of your volunteers. Have them try the same physical activities, as in step 7. Record their new scores in a data table, like Table 1 above, in your lab notebook.

Analyzing the Data

There are many different ways to graph and analyze your data from this science fair project. You should think about the questions you want to answer and which types of graphs might help you discover those answers. Below are a couple of data-analysis options to get you started.

  1. Using the graph paper, make a line graph, one for each volunteer, showing his or her daily dietary score over the course of the whole experiment.
    1. If you need help graphing, or would like to use the computer to make your graphs the Create a Graph website may be helpful.
    2. Look at your graphs. What happened to the daily dietary scores for each volunteer over the course of the experiment? Did they increase, decrease, or stay the same? Was the trend the same or different for volunteers in Group 1 versus Group 2?
  2. Make bar graphs showing the volunteers' scores on each physical activity.
    1. Make one graph for each physical activity. You should have a total of five bar graphs.
    2. Graph each volunteer's first and last day scores next to one another.
    3. Make the bars representing data from Group 1 volunteers one color, and the bars representing data from Group 2 volunteers another color.
    4. Look at your graphs. What happened to the physical fitness level of each volunteer? Did it increase, decrease, or stay the same? Was the trend the same or different for volunteers in Group 1 versus Group 2?
  3. Based on all your data and graphs, what can you conclude about the effects of healthy eating on athletic performance?
icon scientific method

Ask an Expert

Do you have specific questions about your science project? Our team of volunteer scientists can help. Our Experts won't do the work for you, but they will make suggestions, offer guidance, and help you troubleshoot.

Global Connections

The United Nations Sustainable Development Goals (UNSDGs) are a blueprint to achieve a better and more sustainable future for all.
This project explores topics key to Good Health and Well-Being: Ensure healthy lives and promote well-being for all at all ages.


  • Does diet affect academic progress? Modify the Experimental Procedure to determine if a healthy diet helps improve test scores or grades.
  • Rather than tracking the effect of diet on athletic performance, track the effect of music on athletic ability. Have one group listen to fast, upbeat music, while the second group listens to slow music or no music at all when they exercise. Make sure each group exercises daily and track their physical fitness on a weekly basis.
  • See if diet changes how you sleep. Do you sleep better with a healthy diet? Do you think your sleep would be better if you added exercise? Design an experiment to find out! Hint: You'll need to figure out a way of quantifying how well a person slept. One way would be to design a sleep survey for people to fill out. For more information about surveys, try the Designing a Survey guide.
  • In addition to investigating daily limits for the five different food groups, there are a lot of other nutritional aspects you could investigate in a group of people to see whether it affects their overall health and performance, such as amount of sugar, sodium, and oils consumed. To get some ideas of other dietary factors to explore, try re-reading the Introduction and investigating the Terms and Concepts in the Experimental Procedure.
  • One nutritional factor that people try to monitor for different reasons is sugar. There are several Science Buddies science fair project ideas you could check out that explore the amount and types of sugar that are in different foods and how the body digests them, including:


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General citation information is provided here. Be sure to check the formatting, including capitalization, for the method you are using and update your citation, as needed.

MLA Style

Science Buddies Staff. "You Are What You Eat!" Science Buddies, 11 Nov. 2023, https://www.sciencebuddies.org/science-fair-projects/project-ideas/HumBio_p024/human-biology-health/nutrition. Accessed 30 Nov. 2023.

APA Style

Science Buddies Staff. (2023, November 11). You Are What You Eat! Retrieved from https://www.sciencebuddies.org/science-fair-projects/project-ideas/HumBio_p024/human-biology-health/nutrition

Last edit date: 2023-11-11
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