10 Comments

That is a super interesting (and very well explained) break-down of this study. Due to some microbiom dysbiosis, i have been following a ketogenic diet for quite a while now.

It is interesting to see that increase in insulin/glucose sensitivity with the low-carbohydrate group. I am wondering if it is really a negative effect since isn't that what our natural metabolisms are designed to? To have like super high energy available if we eat a high-glucose food just on it's own? (Like which other omnivore out in the wild does that even?).

I am a bit concerned about the long-term effects related to the good bacteria (which I just try to re-cultivate 🤣). So it might be that the ketogenic diet can have overall health benefits but not as a long-term lifestyle (but more like cycling it into a more natural rhythm), but including some natural sources of sugar and starch again at times to keep the microbiom happy.

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I think taking a cyclic approach would be very prudent! Many people advocate for cycling periods of fasting or ketosis for the health benefits but also cycling OFF every now and then for the microbiome benefits and also for the blood glucose and insulin sensitizing effects that eating carbohydrates seems to actually help with!

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It also makes a lot of sense from an evolutionary perspective and when we look at hunter gatherer diets: there is a natural occurring randomness of phases of fasting, and then periods of specific nutrients being available. But not all every time and in the same amounts. Similar to the fasting periods that are never timed artificially.

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I wonder if 12 weeks was enough time to see the benefits of the low carb diet. I remember reading somewhere a study that showed the metabolic changes can take longer to kick in. Personally, it took longer than 12 weeks to feel the effects.

Also, if you try to get enough protein (1 gram per pound body weight per day), while keeping calories about the same, it almost ends up being low carb, right? (Although not necessarily keto)

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IMO, 3 months is plenty…metabolic changes and adaptations can start even after 4 weeks!

True that a higher protein diet can be low carb, but totally be keto a diet should be ~80% fat or so.

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Exactly. That’s why I stopped doing strict keto. Just “prioritize protein” to quote Ted Naiman

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This is a fascinating article; well done.

As I am keto-flexing right now (5 days intermittent fasted keto, 2 days more normal diet), I can attest to the fact that low-carb does reduce sugar cravings for me, on about day 2 of keto.

There are major differences between the approaches of keto or just cutting sugar for endurance activity, like long-distance sports, bricklaying, and other hard physical jobs.

I'm a runner. I can have zero carbs for several days and then run for an hour with energy left to spare. I never seem to run out of energy,even if I've fasted for 24 hours. So this is one advantage I get from ketogenic diet that I would NOT get from simply cutting sugar. When I have only cut sugar, I have to eat way more frequently.

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Thanks so much for sharing your personal experience.

I don't have as rigorous a comparison as you, but find that I can much more easily cut out sugar and keep eating starchy carbohydrates vs. cutting out all carbs completely. I've tried that and it just doesn't work for me.

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The thought occurred to me...

If the low sugar or low carb group did see a reduction in energy expenditure how would they have been able to say for sure that the reduction was due to the reduction in sugar/carb or the reduction in calories? In my mind they should have controlled for calories as well to rule out the potential reduction in energy expenditure due to calories rather than substrate. But I guess it didn't matter since energy expenditure wasn't different.

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That's a great question and I think that energy expenditure would be more affected by body weight/weight loss than energy intake per se. And changes in EE didn't seem to differ when controlling for body weight. But you're right in that controlling for calories would have been the best way to make sure the effects were due to sugar or carb restriction, however, I think they wanted the study to be "free living" and therefore sacrificed some control over dietary input.

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