The document summarizes a study that found lungs are the primary organ for weight loss. When fat is oxidized, 8.4 kg leaves the body as carbon dioxide through the lungs, while 1.6 kg becomes water. To fully oxidize 10 kg of fat, 29 kg of oxygen must be inhaled, producing 28 kg of carbon dioxide and 11 kg of water. The researchers were surprised by these results, which show lungs are the primary means of excreting weight loss from the body through carbon dioxide.