Eat your greens! No more sweets! Drink your milk! No fizzy drinks! Parents are always telling us what to eat but why? Investigate food packaging to find out which foods contain lots of sugar or plenty of good stuff like calcium and fibre. If you have access to the internet, you can experiment with making the healthiest and unhealthiest meals on the McDonalds nutrition calculator. Try out these investigations at home to see what happens if we don’t have enough calcium in our diet or eat too much sugar.
A trip to the dentist
Firstly, let’s look at what different drinks do to our teeth. If you can convince the tooth fairy to leave your teeth behind in the name of science, you can use real teeth. Otherwise, hard boiled eggs are a good substitute*. Pop each one in a plastic cup with a different drink; sugary cola, sugar-free cola, orange juice, fizzy water, tap water, anything you like. If you really want to see what acid does to your teeth, try putting one in vinegar! You might not think that you’d drink vinegar but bacteria in your mouth turn sugar to acid, so sugary things end up being acid in your mouth. This is why it is so important to brush your teeth! Leave the teeth or eggs in the drink for a week and then have a look for any changes.
Want to see what happens to bones when they don’t have calcium in? Try bending a clean chicken bone to see how stiff it is, then pop it in vinegar for three days. Rinse it off and try bending it, has it gone all rubbery? Can you explain why?
*Note for super scientists: are eggs really a good substitute for teeth? Of course your teeth are much stronger than the eggshells but they are made of a similar material. The egg shells contain mainly calcium carbonate while tooth enamel is mainly calcium phosphate but both dissolve in acid.