Healthy Habits Food Science Experiments April 08 2010

The farther away we get from naturally grown food and the closer we get to processed food, the more unhealthy our eating habits become. A diet full of processed food isn't good for the health of our bodies.

This is a valuable lesson for children to hear; more importantly, it's good for them to see and experience through these three science experiments that you can use with your students in the classroom.

The Stain Tells The Tale


Decide how students will be grouped before making final choices regarding the materials for this experiment. Students could do this experiment individually, but it will require more bags and food samples. I suggest partnering students or putting them in groups of three or four to cut down on prep and expense. Otherwise, what you need for this experiment is easy to get:

*Lunch-sized paper bags, one for each food sample.
*Food Samples - Use a variety of foods that range from healthy to unhealthy. Because the bags are small, cut the food into pieces from 1 inch to 2 inches square. For each paper bag, I like to use 2 salty snacks (a Bugle, potato chip, cracker), 2 sweets (cookies, cakes), 2 fruits and 2 vegetables.
*The Stain Tells The Tale Experiment Scientific Process Sheet, one per student

An Easier Version

If you have younger kids, this version will probably be preferred. This can also be done as a demonstration using the materials and directing students to fill out the Scientific Process Sheet as your class checks the food samples each day. The procedure is already typed up on the sheet, which includes the following directions:

  • Prepare the food samples that will go into the paper bags, one type of food per bag.
  • Label each bag with the name of the food sample that is inside.
  • Place a sample of food into a paper bag, one sample per bag. Keep the peel on the fruit samples when possible.
  • Check the samples once each day for two to four days. Draw your observations in the boxes below and describe what happens to the bottom of each bag.

After reading through the directions with your students, work out with them what they think the question should be, leading to something like "What kinds of food make the biggest stain on a paper bag?" As they discover the answer over the next few days through their observations, be ready to discuss with them why they think the unhealthy food is making the bigger, greasier mess as well as what that means for our bodies.

A More Difficult Version

For a more difficult version, use the same materials but place pieces of graph paper in the bottom of each paper bag, cut to fit. The observations will be more time consuming, as students will need to remove the food samples to look at how many squares of the graph paper are covered with (grease) stains in each bag. Students need to take notes on this information during their observation time, and you can use this information at the end of the experiment for data analysis and graphing.

Mold Growth on Red, Yellow and Green Foods

The system of red, yellow and green foods is different from the Food Pyramid, which is an important distinction. When it's time to facilitate this science experiment, talk about the meaning of Red, Yellow and Green foods. It might be easier to start with Green foods, which are items that are good to eat any time. These would include all vegetables (without sauces), fresh or frozen fruit, whole grains, low-fat dairy products and lean meat. Yellow foods are those that can be eaten sometimes (although, peanut butter would be considered on this list, and I don't think I've gone a day without peanut butter in recent memory). Other foods on the Yellow list include vegetables in sauce, fruit juice, grains that are not whole (such as pancakes and waffles), processed cheese, nuts, hot dogs and hamburger meat, and low-fat desserts or condiments.

The Red column is where - for me, a consummate dessert lover - it gets a bit depressing. But I wouldn't let the kids see that. The Red foods are ones that we are supposed to eat on rare occasions, and they include french fries, any fried dough, pastry, cookies, cakes, pies, ice cream, crackers, fried food, bacon and other fatty meat, gravy (duh), heavy condiments, and sugared drinks of various kinds. So basically anything that will provide comfort on really bad days - Red food.

The point of this experiment is to see which kind of food - Red, Yellow or Green - molds the fastest.


  • A variety of foods, including a dairy product, bread product, processed food product, fruit and vegetable. There should be about five different types of food.
  • Mold On Red, Yellow and Green Foods Scientific Process Sheet, one per student

Before you begin, have students identify the foods that are good and bad for you and which they think will mold the fastest - have them fill out the Question and Hypothesis segments of the Scientific Process Sheet. Put the foods in the same cupboard or cabinet and leave them there, checking them each day for mold. Have students record their observations on the Scientific Process Sheet.

Which Beverages Rot Your Teeth?

Observing how certain beverages corrode teeth is always fun as a science experiment.


  • Cups of uniform size to hold liquids
  • Water, vinegar, orange juice, a diet soda, a lemon-lime soda and a dark soda
  • One egg per liquid
  • Which Beverages Rot Your Teeth Scientific Process Sheet, one per student

This science experiment is easy to do with kids of any age. If you have younger kids, run it as a demonstration or have kids work in groups of four. It will take several days to get comprehensive results, so run the observations every two to three days for two weeks. Make sure kids understand that the eggs are like their teeth in that they're made up of some of the same material. Before you begin, read through the Procedure on the Scientific Process Sheet, then fill out the Question and Hypothesis with your class.

These three science experiments provide variety but point to the same concept, which is the more natural the food we eat, the better off we are as far as our health is concerned.