These activities can help to identify fats, carbohydrates and proteins. (And determine which foods fit into more than one of those classifications.)

Fat Content:

Test for fat content in foods by rubbing them on white paper. Fat will make the paper almost clear or translucent. Olive oil and butter work well, but so does bacon. You could use lots of different food to see which foods make the biggest difference.

Starch Content:

Another activity is to test food for starch. Mix some flour or cornflour to some hot water to make an even gluey mixture. Then add a few drops of tincture of iodine. When foods contain starch the iodine will turn blue. Have them try with lots of different foods like mashed potatoes, apples, biscuits, mince meat, cheese….

More nutrition lessons.