I'm onto something using hand shape from swimming to relate to portion sizes of carbohydrates, protein and fat in swimming nutrition.

This can start with the hand on the face to create the cupped hand for the 'catch', and the cupped hand for grains, pastas, and bread. And then use the flat hand shown here for a portion of protein, such as fish, chicken, an egg or nuts.

Before moving onto the clenched fist for fruit & veggies and a thumb for fat. 

All part of a sports nutrition course I am developing for my swimming club.