Extreme wasting leads to death. However, as with many biological processes, small doses of the process or nutrient/supplement are often beneficial even if fatal in the extreme. A micro-experience of wasting comes from fasting which is beneficial. Fasting promotes autophagy - the body's self-devouring of cells when the body begins to look to its own tissue for sustenance. The body is always killing off or consuming weak cells to get on with clearing out the brush and creating new ones. With even light short fasting, this process is enhanced because the body consumes the weakest and damaged cells first. Then -rather than getting into wasting- you return to eating after having done a very light housekeeping. Methinks. Refer to pubmed for more on autophagy studies or not as needed/desired.
Just to be clear because some people are misinterpreting the above, doing a keto diet does not mean you burn your fat until you are down to less than 3% body fat and waste away. That is NOT a ketogenic diet. People on Ketogenic diets still EAT. People are taking the extreme with respect to Keto without taking a moment to understand how it works. Ketogenic plus maintenance caloric intake means you are not eating up all your fat stores.
Actually it is amazing how much good stuff you can eat on keto, given that fat is good. We are not talking about a kale and lettuce diet here.
Thanks. Yeah, just to be clear, I wasn't referring to anything related to keto when I was talking about wasting away. I was just referring to literally what happens to the body when you starve to death from either a lack of food, an inability to eat because of old age or medical condition, etc.