Or that's a half-understood idea some push [1], mostly looking into first order effects, and unaware of the bigger picture (except from cherry-picking this or that pro-keto study, which are themselves a dime a dozen, like most nutrition studies are).

[1] Nutrition in general, is at this point scientifically half-understood. Science has tons of things it still tries to understand and needs to explain on nutrition...

One thing I think that people should be more aware of is that nutrition advice that has a small significance in large studies might be recommended for the general population by health officials, but could be something that is actually bad for you personally. It will be great if we can get a better understanding of nutrition for individual people based on their own genetics, body weight, lifestyle, etc.

The process of converting fats to ketone bodies, and the body using those ketones as energy, is a well-understood process.

>The process of converting fats to ketone bodies, and the body using those ketones as energy, is a well-understood process.

Only at the high level and first order effects.

The idea that this is OK as a diet, and the tradeoffs long term, is a not-well understood process with tons of pro and con papers, as is most of nutrition science.

Ketosis is a terrible process that your brain and body hates.

The converse, too many carbs -- leads to diabetes, the number 1 preventible condition in western societies, which is probably a more terrible process that your body also hates.

This is a common source of confusion, but carbohydrate intolerance is a symptom of diabetes, not a cause. Diabetics that go on Keto diets are still diabetic. If you give them a piece of toast, their blood sugar goes through the roof. It's like that joke about going to the doctor and saying "It hurts when I do this" and the doctor says "Well, don't do that anymore".

On the other hand, eating a whole-food plant based diet can actually reverse type 2 diabetes. People stabilize their blood sugar even while eating things like whole wheat bread, potatoes, rice and fruit, and generally have to have their insulin reduced and then eliminated to avoid hypoglycemia.

There is a theory gaining traction that insulin resistance is caused by fat in our muscle cells that somehow blocks the activity of insulin. So eating a very low-fat diet allows this fat to clear out, allowing insulin to work again, so you can eat carbs without your blood sugar spiking.

The fat in muscle cells is called "intramyocellular lipids". We know that it's associated with insulin resistance, the only debate is whether it's the cause or the effect, or if something else is causing both. Based on what I've read, I subscribe to the theory that it's the cause.

Being overweight or obese is the cause of 90-95% of cases of Type 2 Diabetes. https://www.webmd.com/diabetes/diabetes-causes#1

Being overweight usually is tied to overconsumption of calories. Most people don't consume too much fat or protein: it's just difficult to eat a jar of crisco or an entire ham. However, in western cultures, overconsumption of calories is largely associated with highly processed, sugary foods. Chips, soda, snacks, etc.

I will concede that's not the reason for everyone who is overweight, but for many, it is the case. It's predominantly too many carbohydrates.

Why is it terrible? What evidence is there that your brain _hates_ it?

From what I understand, there is evidence that the brain may function better deriving energy from ketones, and ketosis may be neuroprotective: https://blogs.scientificamerican.com/mind-guest-blog/the-fat...

Well your brain only does it when you’re starved for glucose, for one. If your brain operated better off of ketones it’s hard to imagine why it would preferentially operate off of glucose when it’s available.

But also, have you done it? It feels awful.

That may have been your experience, but plenty of people have the opposite experience.