I've heard from 2 dieticians (professional, not online), that the primary way we lose weight is through our breath. Food we eat is drained of nutrients and exc

I've heard from 2 dieticians (professional, not online), that the primary way we lose weight is through our breath. Food we eat is drained of nutrients and excreted. The excretions are less than the food, and the rest is absorbed into the body. The other excretion we have is sweat, which is primarily salts and water. The only avenue in which we can shed weight is by CO2 exhaled... (I do not have a citation for this from a paper, but heard the same description from 2 different dieticians. I accepted this as fact.)