Keto is short for ketosis. I'm not sure if this 100% correct but it's what happens when the body runs out of glucose and decides to quit converting protein to glucose. It can take days for the body to run out of glucose so it has to be a long term thing. The brain can't run on the same fatty acids that the rest of the body can so ketones are created. Fun fact: The body can burn alcohol and sets it as more of a priority over anything else as we drink more to reduce it. The brain can't run on alcohol so that's why we get stupid. Type 1 diabetics often get mistaken for being drunk when severely hypoglycemic because there's a similar effect. Alcohol also causes a big serotonin rush responsible for the sociable friendly effect. Sometimes it works well for fatties because when their natural insulin drops, their sky high leptin levels can finally signal that they have enough fat storage. The ketones may even power their insulin resistant brains better than glucose giving them more logic and a glimpse of self awareness. This is why the "eat whatever you want" as long as it has no carbs thing sometimes works for the morbid obese if they don't cheat. Eventually they have to start cutting calories because the leptin resistance they've caused from having such high levels has to be regulated. Humanoid bodies are much different than lardoids because we produce much less leptin and is decreased exponentially when nearing essential bodyfat levels. Leptin is mostly produced by fat cells  but is also produced in other parts of the body. Leptin levels are mostly associated with bodyfat levels but their are some associations with carbohydrate intake and blood glucose levels. This is probably why you don't see many competition physique people using keto.