As a toddler my Mom read ‘The Very Hungry Caterpillar‘ to me, and I noticed that the book is still around today. So I thought you might like the following mini-Sankey diagram I found on an educational website.
Of all the energy contained in the leaves (or apples, pears, strawberries …) the caterpillar eats, half turns into feces, and some 33% is for cellular respiration. Only approximately 17% is for growth of the caterpillar. It seemed more than that to me at the time…