Healthy eating and physical activity solutions for kids

Hands-On Food Science for Kids

The science of food and nutrition creates awesome hands-on learning opportunities!  Fun activities help kids to develop an interest in foods and nutrition.

Hear – See – Do Activities

The 2015 Dietary Guidelines for Americans recommends limiting saturated fat intake to no more than 10% of daily calories.  Although dairy foods are key source of calcium, needed for bone growth and maintenance, they are also a source of saturated fat. The following activity helps kids visualize the fat content in different milk products.


  • Milk (skim, whole, and half & half)     •  3 shallow bowls
  • Liquid dish detergent                         •  Food coloring
  • 3 Cotton swabs
  1. Place three bowls on the table and label them skim milk, whole milk, and half & half as shown.  Add about 1⁄2 cup of skim milk, whole milk, and half & half to the appropriately labeled bowl. Have kids look at each type of milk closely and ask:  What differences do you notice about them? What do you think might cause the differences?
  2. Gently add one drop of food coloring to the center of the milk in each bowl. DO NOT STIR OR DISTURB THE BOWLS.  Ask kids what they observe about the way the food coloring looks in each bowl.  Does this observation make sense with what was observed about each type of milk before the food coloring was added?
  3. Dip a cotton swab in the detergent. Carefully touch the center of each food coloring drop in each bowl. Do not stir. Use a different cotton swab tip for each bowl. What is observed? Is there a difference in the way the color looks in the different bowls? What might cause these differences?
  4. Discussion:  The food coloring spreads out most in the skim, least in the half & half, and somewhere in between in the whole milk. Since milk is made mostly of water and fat, the food coloring looks different in each bowl because it mixes easily in water but not in fat. It mixes the most in skim milk, which has the most water and the least fat. The color mixes least in half & half which has the least water and the most fat.

*When detergent is added, movement of the food coloring also varies with the amount of fat and water. The detergent breaks up fat globules and allows them to spread out across the surface of the milk. As the tiny fat globule breaks and expands, it creates movement in the otherwise still milk.