Food is about more than taste. A few quick, easy, and fun kitchen experiments can help your preschooler learn how things we eat affect our bodies:
The Question: Is too much salt bad for us?
The Experiment: Cut off two thick slices of a fresh, whole cucumber and thread a string through each one. Coat one slice with sea salt, and leave the other completely unsalted. Tie each slice on a hanger. Explain to your preschooler that the cucumbers represent their body and the salt represents food and drinks high in salt. In 15 minutes have your child look and see how each slice has changed. Ask him what the "salty foods" did to his "body." The next morning have your preschooler gently squeeze each slice.
The Lesson: Kids will see how the salted slice drips water and can begin to see how salt might make them dehydrated. The next morning, your child will see how the salted slice is weaker and flimsier, like they would feel if they lost a lot of water.
The Question: How does an antacid work?
The Experiment: Explain to your child that our stomachs always have acid or "juices" to help our bodies use the food we eat, but sometimes our bodies make too much of that acid, which can give us belly aches. Put 1/2 cup of white vinegar in each of two mugs. Tell your child the vinegar is a kind of acid. Have your preschooler drop a children's antacid into one mug and watch what happens. After the tablet has dissolved, have your kid sample a few drops--less than 1/8 teaspoon--of vinegar from that mug. Have them eat a cracker, and then using a clean spoon, taste the same amount of the plain vinegar.
The Lesson: When they drop the tablet in the mug, they'll be able to see how the antacid interacts with acid (the vinegar). When they taste the difference, they'll also note how the antacid neutralized the acid.
The Question: Why do we have to brush our teeth?
The Experiment: Explain to your preschooler how an eggshell is made out of stuff similar to our teeth. Have your child gently put an uncooked egg ("teeth") into a large clear glass or jar, and help them slowly pour a dark soda (cola) over the egg, so that it is covered. After 24 hours, have your preschooler investigate the glass and soda. Gently remove the egg and have your child note its color and texture. Ask your preschooler to imagine, then, how soda might affect our teeth. Replace the egg in the cola. Come back in two or three days and gently pour off the soda. Explain that although we don't soak our teeth in soda for days, the effect over the long term is similar when we don't brush.
The Lesson: At the first check-in, your child will see how food and drinks stain the "teeth." At the second, they'll see that the acids and sugars have completely eaten away the "teeth" and why keeping food and drink brushed off of them is very important.