There are two properties that define matter — size and mass — and both of these are determined at the subatomic level by energy and a related concept called force fields. Most of the mass of your body is determined by protons and neutrons, which are made up of quarks. The kinetic and potential energy associated with these quarks is so intense that it makes up 98% of the mass of all matter.
Read more: https://bigthink.com/hard-science/your-body-energy-field-proof-einstein-equation/