I read recently that a fit man with a body fat of 10% has
enough body fat to fast for a month.
But the key to fasting, as Joseph pointed out, is to be fat-adapted, so that your body is readily able to take up fat as fuel. Carb adapted people feel like hell when they fast because it can take days, even weeks for the body to learn to use fat.
Joseph, are you a
vegetarian, or that just happens to be the bulk of your diet by happenstance?
I have been doing a lot of research on this as I am trying to control/reverse my diabetes by diet and lifestyle change. Kind of life or death important to me as I live in the sticks of Africa without access to medical care.
If you feel unsatisfied on a vegan diet, it's probably not the lack of protein, its the lack of fat. Fats are what keep you full and satiated.
Last year I was eating an almost vegan diet, almost entirely off the farm. We have animals and eggs, but since that's a source of income, I was selling them instead of eating them. It was what most people would consider an extremely healthy diet. But I felt awful. I would bonk (hit the wall, run out of fuel) after just two hours of hard work. I didn't feel well all the time. My diabetes, which had been sort of in remission for about 5 years, reared its ugly head, and I started to gain weight.
I have been making changes and trying to convert to more of a keto diet. It's hard because all of our
staple food stuff are starchy - sweet potatoes, cassavas, taro, maize, bananas. I stopped eating wheat entirely, and that alone made me feel a LOT better. It makes me really sick and gives me a lot of digestive problems. I have a disability, and wheat was aggravating the hell out of it, but I never knew, because its something I always ate.
Where I was crashing after a couple hours after a high carb breakfast, I can now take a cup of tea with a spoonful of coconut oil and work until mid afternoon without feeling tired or hungry. That's why your friends put butter in their
coffee.
I eat a lot of greens and eggs, since that's what I have on the farm. I am trying to rebuild our poultry stocks and livestock o that I can add in more meat. My last hatch of chicks gave me 8 roosters and only one hen. You know where those roosters will be going!
I have a harder time now with boredom than hunger. I have always loved good food, cooking, trying new recipes... And this lack of variety kind of sucks and mentally I sometimes feel deprived.