If someone was to try this when they are desperate for food, usually if alone and lost, they could make a bad situation even worse.

To add to this, people can go for a very long time without food. We have the convention in of eating multiple times a day in modern society, but if a human needs to live off of fat stores -- and, later, muscle -- they can do it for quite a while, unless they're very emaciated.

https://en.wikipedia.org/wiki/Angus_Barbieri%27s_fast

Angus Barbieri (1938 or 1939 – 7 September 1990) was a Scottish man who fasted for 382 days,[1] from 14 June 1965 to 30 June 1966. He subsisted on tea, coffee, sparkling water, vitamins and yeast extract while living at home in Tayport, Scotland, frequently visiting Maryfield Hospital for medical evaluation. Barbieri went from 456 pounds (207 kg) to 180 pounds (82 kg), losing 276 pounds (125 kg) and setting a record for the length of a fast.[2]

Water is different -- a human can't go for very long without water. Maybe a week or so, though people have gone longer (albeit that unpleasant things are going to be happening to them). IIRC, the world record is some guy in Austria that got accidentally forgotten about in a jail cell, though he was able to get some condensed water from the walls of his cell.

kagis

https://en.wikipedia.org/wiki/Andreas_Mihavecz

Eighteen days later on 19 April, an officer who had unrelated business in the basement opened his cell after noticing the stench that was emanating from it.[4] Mihavecz needed several weeks to regain his health.[2]

But most people are not really in immediate need of food.