[zemvpferreira]

Might be that fat was as scarce as carbs prehistorically. Have you ever eaten wild game? They are drastically leaner than farm animals. I imagine they were even leaner back when there were more wild creatures competing for the same food supply.

It's not an accident that our palate has evolved to reward us for finding salts, fats, and sugars.

[hnick]

Seems appropriate to mention rabbit starvation here:

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

Meat-only diets are sustainable, but remove enough fat and you'll die.

[yourkin]

Nor fat, nor carbs are an essential nutritional component. The body can not synthesize certain amino acids, but it can convert protein to both fat and carbohydrates by means of gluconeogenesis. If anything, we should have cravings for sources of protein, not sugars. One could argue that sugars provide the burst of energy for the metabolic pathway that could be make it or break it in cases where that burst gives an advantage. This, and not the scarceness argument, which seems just thin to me, although mainstream opinion.

[jsky_goog]

There was a good talk at Carnivore Con in 2019 here (https://www.youtube.com/watch?v=jH7JGM7K-Lc&list=PLluvR68gTT...) about this.

The very rough gist is that there is historical evidence of pre agrarian humans starving to death with stomachs full of lean meat. In a nomadic lifestyle where they chase down prey protein costs too much energy to digest and convert into usable energy.

[1_player]

Fat is an essential nutritional component. As an example, cholesterol is necessary to produce hormones such as testosterone, estrogen and cortisol. Thankfully, it's pretty much impossible to avoid if you eat meat.

Carbs are not essential. You can live on zero total grams of carbs.

Also gluconeogenesis only converts proteins to glucose, not fat, at least not directly.

[yourkin]

Cholesterol is synthesized by the liver, in sufficient quantities: https://www.sigmaaldrich.com/technical-documents/articles/bi...

believe it or not, by your definition carbs are also essential, it’s just that the body can produce them

Protein -> carbs by gluconeogenesis

Isoleucine and phenylalanine are exclusively ketogenic and produce ketone bodies.

Leucine can be used to synthesize fatty acids in adipose tissue.

The only 2 fats that we really need are omega-3 and omega-6, but not in huge amounts, thankfully, both not from meat.

Point is, one can more readily survive without a major source of fat or carbs.

[1_player]

How do you explain rabbit starvation then?

[yourkin]

A quick look at https://en.wikipedia.org/wiki/Protein_poisoning

* it‘s hypothetical

* the ill effect is diarrhea

* some people have lived off a meat only diet successfully

* personal theory is the problem is not excess protein, but lack of fiber and gut biome degradation

Any mono-diet is nutritionally a bad idea, especially taken to extremes. But — one would simply not survive at all on a monodiet of pure fat or carbs.