Our bodies are mostly made of hydrogen (z = 1), carbon (z = 6), and oxygen (z = 8). in our bodies, are there many more neutrons than protons, many fewer neutrons than protons, or are there about the same number of each?

In their common forms, both carbon and oxygen have an equal amount of protons and neutrons, 8 and 6 respectively, while hydrogen has one proton and no neutrons. Since there is far less hydrogen than carbon or oxygen, there should be more protons than neutrons, but not by a lot.