“Excess carbs and proteins are converted into chemical compounds called triglycerides (which consist of carbon, hydrogen, and oxygen) and then stored in the lipid droplets of fat cells. To lose weight, you’re attempting to metabolize those triglycerides, and that means unlocking the carbon that’s stored in your fat cells.
“Losing 10 kilograms of human fat requires the inhalation of 29 kilograms of oxygen, producing 28 kilograms of carbon dioxide and 11 kilograms of water. That’s the metabolic fate of fat.
“Then the duo calculated the proportion of the mass stored in those 10 kilograms of fat that exits as carbon dioxide and as water when we lose weight. By tracing the pathway of those atoms out of the body, they found that 8.4 of those kilograms are exhaled as carbon dioxide. Turns out, our lungs are the primary excretory organ for weight loss. The remaining 1.6 kilograms becomes water, which is excreted in urine, feces, sweat, breath, tears, and other bodily fluids.”