so yep I can agree with the point around permanently low carb being bad for metabolic flexibility as to be in ketosis for fat loss, only works well when one can include carbs and be back into ketosis quickly (I.e low carb during the day, one carb refeed in the evening, back in ketosis within 2 hours). Now that only works when one has metabolic flexibility (otherwise it takes too long to get into ketosis) but to get to that point one has to become fat adapted (I say fat adapted as my understanding is that the body will become ‘carb adapted’ way quicker and easier and it’s just not an issue for the vast vast majority of people anyway).
but, how does one become fat adapted without forcing the body into ketosis (either low carb or fasting or both) and staying there for periods of time?
ive always seem metabolic flexibility as the nirvana really, benefits of fat loss from keto (plus better endurance performance for those who train that way) but the performance and aesthetic benefits.
the other points above around high protein (rather than high fat keto) are interesting as I’ve looked my best off a very high protein diet. For years I was 400g protein a day (220 bw) with approx 150g - 200g carb and 100g fat - same Cals with lower protein and higher carb and I look softer with no noticeable performance gains (this isn’t backed by anything scientific- just my own experience)
I am not sure what I said about protein? or maybe you were referring to others' points?
You are somewhat incorrect about the carb adaptations. People who are skewed toward carb adaptation tend to be lean (see the Japanese thread above).
This makes sense with some thought and some basic biology. Basically, you have to choose what you are going to use in the Krebs cycle to create ATP - fat or glucose. The control switch for this is Pyruvate Dehydrogenase Kinase. If PDK is elevated, it is switches on fat burning and switches off carb burning - like the switch on a train track.
Now, this is not to say it is all or nothing, it is almost always a mix of carbs and fat being used, but elevated PDK = more fat for fuel and less glucose.
The point here is that elevated PDK is a big part of metabolic flexibility and ketosis or not, people who are fat have elevated levels of PDK and are thus better at burning fat and worse at burning carbs than someone who is metabolically healthy.
This is also a big reason why high fat diets and not high carb diets are the most reliable method of inducing diabetes.
If you follow it through, people overeat, blood sugar elevates, glucose stores become full, glucose becomes stored as fat, fat stores become full, PDK elevates to help burn off excess fat, this makes it harder to burn carbs, cells that do get carbs burn them more slowly and it this takes fewer carbs to elevate blood sugar as they aren't being burned in the cells and the cells just remain full as fat is burned preferentially, elevated blood sugar is thus stored as fat, fat is elevated, PDK goes up more, etc.
In other words, people who are obese are pretty good at burning fat already and not carbs.
Now, the brain cannot burn fat, so fat people don't go into ketosis because they don't need to.
In other words, I get that people use "fat adapted" as a means of describing the idea that our brain switches away from using carbs as an energy source - but this is the only difference between an obese person and a person who is either starving or in ketosis. People who are obese are already burning fat preferentially because of elevated PDK.
But this is probably part of the reason keto can be effective - if you suck at burning carbs and you are good at burning fat...then eliminating carbs will eliminate that part of the problem.
This strategy, however, only serves to elevate PDK and hinder your ability to tolerate carbs even more.
At some point, if you follow the logic, you would need to convert and store carbs as fat before you could even burn them for fuel.
This situation, with elevated PDK can cripple your metabolic flexibility - it is not easy to reverse. PDK inhibition has shown potential for cancer treatment, diabetes treatment, etc.
But basically, some of the metabolic derrangements of obesity are imitated with starvation and ketosis, which seems counter intuitive at first but makes sense with a little thought.
Or, I could be crazy
