The keto diet induces a metabolic change called ketosis, which causes the body to burn stored fat as energy rather than blood sugar. One of the side effects of the process is that it changes the way the body handles oxygen deprivation.
David Ludwig, professor in the Department of Nutrition at Harvard T.H. Chan School of Public Health, explained in the article that ketosis reduces the amount of carbon dioxide produced by the body in relation to the amount of oxygen it consumes. The buildup of carbon dioxide in the bloodstream is what triggers the need to breathe, he said, so being on the keto diet could enable someone to breathe less often.
However, Ludwig cautioned, the long-term health effects of the keto diet have not been studied.