Keto 10X And proteins also share the same fate, with the exception of a small part that becomes urea and other solids that are excreted in the form of urine. The only food that reaches the colon undigested and intact is dietary fiber (an example of this is corn). Everything else is absorbed into the bloodstream and organs and then stays there until we vaporize it. The kilos that go in front of the kilos that go out We exhale 200 grams of carbon dioxide every night At school, we all learn that, according to the first principle of thermodynamics, the energy that enters, accumulates, is expelled or both. But the concept of energy is something really confusing , even for health professionals and scientists studying obesity . The reason we gain or lose weight is much less mysterious if we keep track of every kilo of food we eat, and not just those enigmatic kilo joules or calories.