Fats aren't attached to oxygen (looks like maybe what makes a fat a fat is the functional group that is bonded to a carbonyl).Yes, covalent bonds are chemical bonds, not all chemical bonds are covalent, there is the unique distinction.
So I get it, you don't know the specifics on how our bodies access that energy, thankfully I do.
Our bodies must access to these associated chemicals from our dietary intake.
Proteins are a peptide chemical bond, aka p-bonds.
Carbohydrates are linked by covalent bonds, aka glycosidic bonds.
Fats essentially are attached to oxygen by covalent bonds.
This is how our body uses dietary intake of Proteins, Carbs & Fats to form energy.
Anyway, so it is your perspective that we use mass that we condone throughout the day to provide energy to our bodies? We convert some of that mass into energy, correct?
If so, let me ask some other questions (maybe a series, in subsequent posts)
Do you believe that the number of atoms from each element that enters your body has to equal the number of atoms of each element that leaves your body (or accumulates, which is weight gain)?