Wording of this Handout:
Because it has protein in it. Protein is a chemical. You cannot see it with your eyes unless you use a powerful microscope. Protein from meat helps to build your body and repair it.
Some people choose not to eat meat. They get their protein in other ways. 100 grams of beefsteak protein is about the same as the protein in 2 eggs, half a litre of milk, 70 grams of cheese, 140 grams of fish and 70 lentils.
Without protein, your muscles would shrink and your body would fall to pieces