If you humans were reduced to your constituent elements, would there be anything left beside chicken grease and corn oil?

don't forget the starch from french fries

You start your question "If you humans were........." rather than "If we humans were....." How do you class yourself I wonder?

those are not elements.

Constituent elements of the human body are carbon, hydrogen, oxygen mainly with some trace amounts of others.

wikipedia:

Almost 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium. All 11 are necessary for life. The remaining elements are trace elements, of which more than a dozen are thought on the basis of good evidence to be necessary for life. All of the mass of the trace elements put together (less than 10 grams for a human body) do not add up to the body mass of magnesium, the least common of the 11 non-trace elements.