I know. It's not for everyone.
By the way, I'm not sure I want to live to 105 unless I'm in great health. In fact, I know I don't :-).
I've always leaned toward trying to watch calories but nowhere close to 1000 calories a day. It is pretty severe but with good reason, in my case. I spent three years on dialysis and, through my own research, determined that, among many other health benefits, reduced calories and a plant-based diet might cause my kidneys to recover some function -- at least enough to get me off of dialysis after three years.
I started the diet, among a few other lifestyle changes, and got exactly what I expected. It resulted in a huge improvement in my kidney function, enough to get me off dialysis -- including several other positive changes.
I love food, or used to. But I love not being hooked up to a dialysis machine even more :-)!