Dear lord, man, what even is the thinking behind such a question? I mean seriously, did you just ponder under the shower and did not think what you are asking about here? I'd be really interested if, for one second, you considered that what you are asking about here and what we write about here are actual human beings. Human beings who lived lives, felt pain and joy and happiness and sadness and the case of the Holocaust experienced things that to us, as people who didn't have to live through that, who weren't victimized by one of the objectively worst regimes in history, are of such unimaginable scale and horror that it sometimes boggles the mind.

I do this for a living and have been researching this for over 10 years and I as well as to colleagues who have been doing that even longer than I are sometimes so shocked, so overcome with revulsion by the horror that humans were able to inflict upon other humans that we have to turn away in disgust from what we read and just take a day or two. I have seen a lot of things on this forum, from horror voyeurs, who only want to know about mass shootings and how long it takes for people to die in gas chamber to Holocaust Deniers, who I know are some of the worst human beings walking this earth right now. But with them I know that they are fascists and am intellectually aware as to what kind of ignorance and hate that entails towards other people. What baffles me so about this is the intellectual detachment and the attitude of treating the past lives and stories of actual human beings who suffered immensely either as mere exercise in a kind of curiosity that does not advance overall human knowledge in any sensible direction or as sick joke.

You want to know about how people survived in the camps and during the Holocaust? You want to know what it was like for people, fat and thin, educated and uneducated, religious and atheist in these camps? Well, do I have some things for you.

The following are excerpts from the book Humans in Auschwitz written by the former Buchenwald and Auschwitz inmate Hermann Langbein and it is largely based upon the recollections of prisoners who through luck or help from others managed to survive the ordeal of the camp:

NSFL warning here btw.

Pelagia Lewinska describing the live in the Auschwitz Birkenau women's camp:

No light. The barracks are never light. Movement and noise rule like in a bees' hive. One hears women's voices in a myriad of languages – Polish, French, Czech, Russian – who are missing even an ounce of energy, of emotion. (...) In a space not even as big as four square-meters it is not easy to create any sort of liveable space. Despite that the barracks are filled with 800 to a 1000 people and full to an extent that seven or eight women share one bunk bed. In the bunk beds the lowest level is made up of the bricks that make up the floor of the barracks. It is like crawling into a little dog house, surrounded by wet bricks one is robbed of all breathable air. The highest level of the beds is immediately under the roof; in Winter all the water comes through and in Summer one feels like being roasted alive. The only thing one sleeps on is straw sacks made of paper filled with tiny amounts of wood shavings. (...) It is dark and one has to organize one's whole life in that little bunk one shares with 7 to 8 others. One's life is reduced to sleeping and eating if something is available.

Describing the prisoners in the camp, former prisoner Desire Haffner wrote:

They looked like skeletons, with shaved heads, bodies smeared with blood, skin full of scurf and dander. It was an effort to recognize that these people were women. The lack of any sort of hygiene was even more noticeable in the women's camp than in the men's camp, especially because of the intensive smell of thousands of women not having washed themselves in months lingering in the barracks. Their work was as hard as the men's and in general they even wore worst clothing. Sometimes one saw them without hats or shoes or even just naked.

Those who due to the combination of constant violent abuse – Langbein e.g. himself was strapped in the so-called Boger Swing; a contraption invented by a guard named Boger, prisoners had their ankles and hands bound together, were suspended from the ceiling and Boger beat their testicles with a cudgel so that they swung around the room –, the lack of foot and the hard work lost their will to live became living Skeletons known in the camp as "Muselmänner" (Mussulman).

One of the Polish prisoner doctors, Władysław Fejkiel, described them as follows:

The symptoms of severe hunger can be divided into two phases. In the first one, people emaciate, their muscles become weak and their movement becomes severely reduced. During this time no deeper damage is done yet to the organism. Aside the slowness of their movement and their general lack of strength no other symptoms appear. Aside a certain excitability and irritability no psychological change takes place.

The border between the first and second phase is hard to define. With some the change happens fast, with others very slowly. In general, one can say that the second phase begins when a person had lost of a third of their body weight. Aside further emaciation the look on their faces begins to change. The eyes become dull, the face takes on a non-caring, thoughtless and sad look. The eyes recede into the head and become fallen in. The skin takes on a grey hue and becomes thin, paper-like, and hard. It also peels. They were very susceptible to infections, especially scabies. Hair becomes colorless and breaks easily. The head becomes elongated, cheekbone and eye sockets become very noticeable. The sick person breathes slowly, speaks quitely and with great effort.

Depending on the duration of the hunger smaller or larger edemata begin to appear. They start on the eyelids and the feet and change their position according to the time of day. In the morning and during sleeping hours, they are most noticeable in the face. In the evenings they appear on the feet and legs. The edematas develop with increasing hunger and spread in people who have to stand a lot. First onto the upper part of the legs, the testicles, and the buttocks but also even to the stomach. In addition to the swelling, there is the diarrhea and sometimes the diarrhea precedes the swelling.

During this phase the patients became apathetic. They isolated themselves from their surroundings. If they could still move, they only moved with very slow speed and without moving the knees. In addition they suffered from decreased body temperature and began shivering constantly. If groups of those suffering hunger were observed from afar, one had the impression of praying Arabs. Hence the common name for these people in the camp: Mussulman.

Haffner again on the same people:

The extreme emaciation was the most noticeable thing about them. In just a few days, they lost 10, 20, 30, even 40 kilogramm. A total reduction of the body to the muscles. Their eyes are sunk deeply in their holes. Their cheekbones protrude, their cheeks look hollow and their chins jump at you. Their limbs are purse bone covered with a grey-yellowish peeling skin, their rips protrude from their flesh, their stomach is hollow. Their buttocks are mere muscles mass and defecation is constant. The weight of these grown people is about 25kg [55 punds]

And so it was. According to the notes of Otto Wolke who noted weight and height of prisoners in the Quarantine Camp for the SS one can glean the effects: Prisoner of a height of 156 cm weighs 28kg. Another one with 167 weighs 34,5kg. A third with a height of 171 cm 35 kg.

As former prisoner Aron Bejlin describes, there were only two taboos in Auschwitz; things that were not talked about: One was the crematoria and the other one was food.

Talk of food triggers the reflex of stomach acid production and thereby hunger. When somebody started talking about food constantly we knew that was the first sign of becoming a Mussulman. (...) In short he will become a walking corps.

One of the men who had become such a walking corps but came back from it, Max Mannheimer describes what this does to a person:

I was always on the lookout for those who peeled their potatoes and begged them for the peelings. I ate the peelings. No, I don't eat them, I devoured them. Like a mad man. Like an animal. As if I was afraid. Maybe also because of the raging jealousy of all the other potato peel eaters. I am ashamed – and always on the look-out for those who peel their potatoes.

As Primo Levi wrote:

14 days after the begin of my imprisonment in Auschwitz I already felt the hunger. The kind of hunger free people do not know. The kind that causes dreams at night and lives in all our limbs. My own body is no more: The belly swollen, the limbs withered, the face swollen. Who could ever imagine not being hungry ever again? The camp is the hunger. We are the hunger ourselves, the living hunger.

Also writing on the hunger doctor Lucie Adelsberger wrote:

Those who truly know hunger know that it is not just a vegetative animalistic reaction of your body but instead it is a nerve-shattering pain, an assault on your personality. Hunger makes evil and destroys one's character. A lot of what seems incredible to the outsider among the prisoners is understandable under the perspective of hunger.

So, again, these are real people in their own words. Real people who had to suffer the hunger, the deprivation, the torture and so much more. People who have felt these experiences that to us who have never suffered the hunger of Levi and others can never be truly understand and can hardly be conveyed in words. But instead of an ounce of empathy, what you want is intellectual detachment and reduce them to charts about fat people instead of knowing more about their experience.