This came up in conversation last night with a friend, and the article is both factual and made me chuckle. I figure some biohacker/nutritionist folks on HN might enjoy it, either the humor or addressing any bad facts.
My best understanding is that most of our weight loss is in the form of gas as we exhale the carbon from our bodies after using oxidation to split up carbohydrates which are made up of carbon, oxygen and hydrogen. Plants take carbon from the air and use it to build itself, using the power of the sun to break up the CO2 reusing the carbon, releasing oxygen. Our bodies then consume that plant (or an animal that ate it) extracting the carbs for energy and saving them for later. As we burn the fat by breathing in oxygen, we break down the carbs, expelling most of it as C02 gas.
_"...when 10 kg of fat were oxidized, 8.4 kg were converted and excreted as carbon dioxide (CO2) via the lungs, and 1.6 kg became water (H20)."
Enjoy!