Dietas done in South America (to the best of my knowledge) provide some food for the seven days (or however long you do) but they are unseasoned items like boiled potatoes, rice, boiled green plantains etc. Not appetizing even when you're stomach is growling. You are instructed to read, if you would like, for no more than an hour a day, write as much as you want -- otherwise, you are to just sit there.
My camp was the last stop on a dirt road, five miles in, running through a national forest. It had a creek running by it and seemed to be a long way from anyone else - pretty much all I wanted. After the brief setting up of the hammock tent there wasn't much else to do so I created something to do - build a fire using the flint stick I purchased at REI a few days before. I quickly learned that making a fire with just about anything is easier than shooting a spray of sparks onto what you thought was dry tinder only to have it smoke languidly. Eventually I went to the Bic lighter and had a roaring fire going which I proceeded to sit by for most of the rest of that day and tend.
Through the following two days and three nights, I realized why you are supposed to eat nothing and do nothing in these rituals. Eating generally requires you doing something to prepare or in exchange for the vittles which is probably why they bring the food to your tambo during dietas. A fire provides warmth, comfort and in a way it's another presence that helps you not feel alone because it requires your assistance to remain alive. All the things I found myself doing were subconscious ways of trying to distract me, to keep me from stillness.
On the last full day I decided to not build a fire, read at all or contemplate anything too much - simply just be there. Granted I wasn't in any sort of extreme weather requiring excessive thermal protection, but what struck me was how little it really takes to survive. Not eating for three days wasn't pleasant but it really wasn't that bad. Periodically food would pop into my mind I began to see how much of our time is spent either consuming or preparing to consuming (cooking, shopping, driving -- and of course working to pay for it all). Doing nothing was the hardest part or the experience. Relaxing should be easy but why couldn't I? We are continually looking away from our own reflection, unwilling to look it in the eye because it in essence is asking "why? Why are you continuing to lie to yourself, to be miserable?" Deep down I think everyone knows they are responsible for their own fate yet many feel impotent seeing no way out of "hell" and consequently consume while pointing fingers at something or someone.
Food is comforting because it generally is associated with safety but have you ever seen a fearful person who feels safe enough? When do you have enough guns, money, sex? It's never enough because enough is a state of mind that cannot be conquered through greater and greater quantities of anything. There only is what is and how we each choose to interpret it. We've bought a lie that there is one right way to be and someone else can tell us what that is. Who is it that is choosing to follow that someone else? Most people want to be told what to do and be kept comfortable instead of facing the reflection in the mirror because the real question behind all the other bullshit is "who are you?" or "what do you want?" It seems like an easy question to answer but how much of what you would list is situational based? If the world ceased to be as it is now then what would be the point of your life, your desires? What would you do? Who would you be? It's a question that can never be completely answered but instead is discovered moment by moment as you experience it by allowing false beliefs to perish and the unknown to blossom.