Extreme weight loss - what's the most a human can lose and survive?

Hopefully the title’s not too confusing - what I mean is, what’s the maximum amount of body mass an otherwise healthy human (female or male) can have surgically removed at once and still remain alive and concious after the event? Don’t worry, don’t need answers fast on this one.

For instance, you don’t need your arms and legs, so amputate those. You can survive on one kidney, one lung and with some of your liver removed, so those could be removed. Appendix can be removed, as can tonsils. External ears, the nose aren’t needed for survival, slice those off. You can remove adrenal glands, so goodbye to those. For chaps, well, you know.

Wiki has a list of -ectomies, what surgeons can slice out of you, but I don’t know how many of those would be survivable all at once and how many are mutually exclusive. Whatdya reckon?

I don’t have an answer but you might want to read Survivor Type by Stephen King.

They taste like ladyfingers.

Stop that, you’re making me peckish!

Well, no, you can’t remove adrenal glands. You’ll die of Addison’s disease.

You can remove adenoids.

Close to this I would assume

or this

You can have both adrenal glands removed in an adrenalectomy, afterwards you’d be hooked up on steroids like hydrocortisone and fludrocortisone for life.

NM no new info