I have read in many biology textbooks and scientific journals that "you create your own bodyweight in ATP each day", but they are all just stated as facts. I have yet to see a study or article that explains how this was determined and what assumptions or observations were used.
For example in the Wikipedia ATP entry "Other processes regenerate ATP so that the human body recycles its own body weight equivalent in ATP each day." This has a footnote which links to Opening and Closing the Metabolite Gate in PNAS. Once again it is just stated as a fact "On any given day you turn over your body weight equivalent in ATP" this time with no footnote.
Has anyone come across anything with actual calculations of how this was determined? Is it based on calories eaten, or oxygen consumed, or extrapolation from a single cell, or something else?