Hi Madeline. Dr. Fung has talked about such people. The example I remember him giving was Asian people who eat a high-carbohydrate diet such as lots of rice. His point was that they often are eating the carbs just once or twice during the day. Even if there is a stout insulin response, it’s not occurring many times per day, leading to a lower overall average level and less insulin resistance, if any. The general benefits of eating less often - that apply with all forms of eating for some (most?) people, apparently - apply there too.
Very good question. I think it’s a self-fulfilling prophecy - that those for whom the standard LFHC is really bad, will often do very well eating ketogenically. My gut feeling - sure, genetics plays an important part, but at the present time, vast numbers of people are becoming overweight/have metabolic syndrome/pre-diabetes/diabetes due to that very LFHC eating, especially with the prevalence of snacking and eating meals “just because it’s time.” The CDC says that 1 in 3 Americans will be diabetic by the year 2050 (good grief!). To substantially reverse all of that, the diet and frequency of eating, and then see a large preponderance of good results should be no surprise.
Metabolic flexibility - I don’t know about this. Perhaps I’m not understanding, here. On the face of it, doesn’t sound like that would require higher carb input, to me, i.e. the liver normally will make plenty of sugar for the blood, even if no carbs at all are being eaten. Personally, in four months, I’ve never felt nor even dreamed that I “needed” higher carbs.
That said, I do take in “too many” carbs every so often, once a week at least, on average. I lost weight fairly fast in the beginning, so assumed all was well, and have never tested myself for ketones. I notice that fasting really helps with weight loss, and assume it makes up for some of the too-heavy-on-carb days.