I had this idea that somehow the slaves in these two jobs probably got a miserable bowl of gruel once a day. How long they lived I can’t know, but I presume they kept them going with just enough to make them work. It’s amazing what the human body can withstand when required. The only immediate needs is air. Next comes the body temperature. Somehow and someway you need to keep warm enough not to lose core temperatures. Finally comes water. You need enough water to keep the system cooled and to keep circulation going just like a car needs water in the radiator.
After all that, if you have enough fuel in the tank to at least slow starvation you can keep going though admittedly hunger has a way of simultaneously sharpening and dulling the mind. The sharpening relates to seeing the absolute need to get fuel in the form of calories. The dulling part comes from a low energy setting on the brain that allows you to focus on one thing like staying alive while ignoring higher needs such as satisfaction or even the more intense areas of self awareness. This is survival mode. You’re no longer worried about how dissatisfied you are with your accomplishments to date but instead how you’ll get the next meal while not freezing to death. Life becomes simple. It is clarified down to the act of preventing death.
You can go for extended periods without food and this is why people find a way to survive in difficult circumstances by drinking water and wearing clothes to keep warm. Food is helpful but not essential right away as much as we have been conditioned to believe. This is why people can fast for days and sometimes longer without severe health concerns though it applies to healthy people and not diabetics or others with health problems.
Just be aware that your first concern beyond breathing is body temperature preservation and your focus will keep you alive long enough to find water and then food in that order or priority.
Caution: This is for informational purposes only and is only meant to get you thinking about surviving without food in a survival situation where none or a limited amount of food is available. Read other literature on the subject and come to your own conclusions. Consult a physician if you plan to test your ability to go for any period without food such as a fast.