... I am going to create a new thread that deals with what science actually says about nutrition versus what we are told by people who either do not bother to research the science or do but distort what the science actually says. To respond to your post here, I will say this:
(1) People on low fat diets do need to worry about getting enough protein. Yes, they can "survive" on relatively little, but that is not optimal health. It is just something to be watchful of for people on high-carb/low-fat diets. People on low-carb/high-fat diets do not need to worry about it because by definition they will eat plenty of protein (unless they were to eat exclusively butter, which nobody does).
(2) I don't know anything about water fasts, so I won't comment.
(3) The body will burn carbs (glucose) first and then fats (ketones) for energy. If you do not eat carbs, then it will just burn fat (ketones). It will not burn protein unless you are starving (as in, on the brink of death due to starvation).
(4) Tubers are not "clean energy." Potatoes are toxic unless cooked. Think about THAT.
(5) Fiber is not essential for digestion. It interferes with digestion, by definition. It is INDIGESTIBLE material. Animal foods liquify in the stomach and pass through the intestines within 1 hour, where the nutrient-dense liquid is absorbed through the intestinal walls. I can go several days without ANY bowel movement at all on an all-meat diet, and then it will be small, soft and easy. Absolutely NO problems with digestion on an all-meat diet. You obviously have never eaten an all-meat diet or you would realize how ridiculous it is to claim that such a diet causes any digestive problems at all. It might take a couple of days for the intestinal bacteria to adapt to the new diet, but then it is smooth sailing. MUCH better on all meat than all plants (and yes, I have tried both diets).
(6) Do not make the mistake of saying a "pure protein" or "pure fat" diet. That is hyperbole. There is no such thing. I am talking about a moderate protein/high fat/low or no carb diet (mine), compared to a low to moderate protein/low fat/high carb diet (yours). Do not use hyperbole or inaccurate statements to define our terms.
(7) John McDougall. Ah yes. I read his books and he is one of the guys I believed when I tried a vegan diet. Now that I have learned more, I consider McDougall to have stolen money from me when he sold me his books. He has NO IDEA what the research says. Even in the interview you posted, if you listen carefully, you can tell he has NO CLUE. He has NOT READ the actual studies he cites. It is obvious. He LIES. He takes things out-of-context, and he misrepresents.
I listened to the interview you posted. First, the person who posted that picture of Atkins is also a liar. That is a Photoshop, as Atkins was never 300 pounds+ in his life.
Second, McDougall made several statements that were false or red herrings or other logical fallacies, and Atkins called him on most of them. Including:
- McDougall claimed Atkins favored a "high protein diet." No, it is a "high fat diet." Big difference.
- McDougall cited a study that was of people who ALREADY WERE ILL WITH DIABETES, and then attempted to extrapolate that to the general healthy population. This is dishonest.
- McDougall cited another study where the researcher used a bogus method of the Glucose Tolerance Test (Atkins called him on it).
- McDougall cited another study of "high fat diet" BUT that diet was ALSO HIGH CARB, not LOW CARB. Therefore, it is IRRELEVANT to the discussion. Atkins called him on it.
- When McDougall got into the topic of ketosis and tried to imply that a diet where ketones are released must somehow be a diet that "simulates sickness," I had enough of his dishonesty. I did not listen to the rest of the interview. If you have something specific to talk about, let me know.
Regarding the sugar, it was with people who were (a) AREADY DIABETIC, and (b) EATING A HIGH-CARB, LOW-FAT DIET already. Nothing changed except an increase in carbs. I would have to know more about the study, but McDougall is very dishonest about the things he claims.
I once saw McDougall claim that Eskimos have an average life span of 27 years. I don't know what context, but if he means modern Eskimos, they also have a very high alcoholism and suicide rate. This has nothing to do with nutrition. If we look at the research done on them 100 years ago when they were eating their traditional diet (100% animal foods), they were extremely healthy and lived into their 90's if they did not die of blunt force trauma or starvation (not always easy living in the Arctic).
The other link you gave does not say what the diet was. Just "high fat" means nothing. Was it also high carbs? This is the type of BS that gets thrown around in the media because they need sensationalism to report.
(8) Finally, amino acids do not irritate the body. They are a necessary part of our cell structure. The PH level of the blood is NOT regulated by food and has nothing to do with food. That argument is complete horsesh&t.
You eat whatever you want, and I hope you are healthy. I will post a new thread on the science of nutrition because that will show you what the REAL SCIENCE says and why so many people have it wrong (it has a lot to do with big government).
All the best.