So I can't answer your question exactly, but, as many here know at this point, I have been suffering through an illness where I have not eaten any solid food since last August (please no medical advice). Before I got, with the help of doctors, settled on a liquid diet of 6 Ensures and 4 V8s a day, I lost 80 pounds- 260 to 180, I was dizzy and lightheaded all the time from the lack of electrolytes, and while I still don't have much energy and have to rest for a while after walking the dogs for half an hour, I couldn't even walk a couple of blocks.
That said, my blood panels show everything is normal, so I'm clearly not dying. It's not exactly a great quality of life, especially since our entire society is based around food in every conceivable way, but it is survivable. In fact, one good thing came out of it- I no longer have high blood pressure or high cholesterol, so I don't have to take pills to counteract those anymore.