Thanks for posting this, this is something I've wondered--in an extended fast, net daily oxidation of glucose (loss from the system) has been shown as low as 24-30 grams per day. But if you look at red blood cells--lacking mitochondria, glucose isn't terminally oxidized there, only broken down so far as pyruvate or lactate, producing energy through fermentation, and then the metabolites are mostly resynthesized into glucose in the liver. So an obvious question from that is--what percentage of the brain's energy might be supplied through a similar cycle, with the brain exchanging lactate and pyruvate for glucose?

Dr Eenfeldt has published a big, overview article on the Ketogenic Diet and ketosis, inc. benefits, side effects, etc.

http://www.dietdoctor.com/low-carb/keto#intro

I agree with Thud: not everyone does well on long-term ketosis.

Short-term ketosis over a couple of days, is okay for me; but long-term, nonstop, heavy-duty ketosis (much below 20g carbs/day for weeks on end) induces increasing depression to the point of not caring whether I live or die... a counterproductive state in every way. My brothers are the same way, so it could well be genetic.

There are many people who can't tolerate long-term ketosis without depression, so it's a good idea to keep an open mind about it being the right solution for everyone.

How do you do "short term ketosis"? Once I am out, eating too many carbs, it takes me four days of very diligent eating, VLC to get back in. I go through hunger and cravings again, much easier than the first time, but there. Does fasting for one or two days put a body into ketosis for those days? And then eating more than 75g of carbs on non-fasting days takes a body out?

I am really curious, is a body in ketosis when fasting short term?

The Carb UP/Carb Down way of eating has one day a week with high carbs and 6 of VLC. Just as a body is getting back into a good ketosis, it is bumped out again. Did not work for me! It really works for some.

As Jenny said, we all need to do our N=1 experiments and find out what it is that is good for us and we can live a long, healthy life on.

One other tid-bit that I'd like to point out is that what was optimal for me 2 1/2 years ago may or may not be what is optimal for me today. My metabolism had a lot of healing to do and for that purpose I'm convinced that a VLC/Ketogenic version of low carb was more effective. At least it was for me. I started off this WOE with net carbs in the neighborhood of 30 - 45 most days. I ate that way for 8 or 9 months. While this was effective in getting my diabetes under control and losing weight, I was still insulin resistant. My everyday BG levels were still elevated and it didn't take that many carbs in a meal to spike my BG well above 140. I was walking daily and eating consistently low carb. I was surprised that I was still getting postprandials that high from a 15 net carb meal.

As I approached the end of my first year with this WOE I started tweaking the diet. I experimented with intermittent fasting. I worked on eliminating stacking after dinner. At the 1 year mark I was doing a very low carb/keto version of LC (20 net carbs). Of course I cannot definitively say what I did that was most effective, but that period in my diet was a game changer. My daily FBG fell to normal levels (upper 70's to low 90's) everyday. My postprandial BG readings flattened to the point where they rarely cracked 100. I only did VLC/Keto for about 3 months. I was still morbidly obese. A cholesterol issue resulted in me changing things up again. I went back to eating 15 to 20 more net carbs per day. My BG numbers stayed terrific. I can eat twice the number of carbs as I was eating and still have my BG remain at low, healthy levels after a meal. I can't remember the last time I had a reading above 110. My BG still rarely cracks 100. So what ever it was that I did in that middle part of my journey, it seems to have done my body good. My insulin resistance is much improved. The sugar that I eat has a place to go without spiking my BG. And I'm eating more carbs than I did before.

As others have said, I'm a little hung up on the value of micronutrients found in fruits and vegetables. Personally, I think we humans always think we know more about something than we really do. We have been beaten over the head with the idea that we need the full spectrum of nutrients from eating a diverse diet that includes lots of grains, seeds, fruits, nuts, vegetables, and legumes. How much of it is true and how much of it is just a sales pitch remains to be seen. The skeptic in me tends to land on the side that believes that the value of micronutrients is way overblown. I have been taking supplements for more than a year now. I will likely discontinue them when the bottles run out. My maintenance diet is not VLC/Keto. A lower carb diet seems to work best for me. I like the variety and that should provide all of the micronutrients that I need.

Peter Attia, one of the original founders of NuSci along with Gary Taubes, posted about ketosis recently: http://eatingacademy.com/weight-los...ons-of-fat-flux

It's pretty extensive and in-depth, lot of biochem if you like that stuff, but handily explained.

That looks like a great site Jenny. I've seen that Peter guy interviewed once and liked him immediately and even more when I learned he liked the water and swimming. I'll check it out and Keto on!

Glad to see Peter is posting again. He took a long sabbatical from this site when he was part of NuSi. Here's hoping this is the beginning of some regularly posted topics. Thanks for the heads up on this!

I read that dipping in and out of Ketosis could trigger metabolic syndrome. During the time I was in Ketosis, some family came to visit and I ate too many carbs and could feel myself being booted out of Ketosis. It wasn't pleasant...I lost energy and became irritable and gained weight. After the visit I jumped back on the lc wagon but it was about a week before I felt my energy shift back into Ketosis. I was worried that my body would have problems switching back and I really missed the clarity, energy and optimism. So when I did cross over again I was so relieved that I made a decision to stay in Ketosis as long as I could. Originally I was only going to do the 2 week induction but after my research I'm going to try to stay fat adapted 3 months or longer on 30g carbs max. I never knew it could feel this good and I don't want to lose it again. I'm also worried that by dipping in and out, the benefits of living in Ketosis could be diminished.

Hi Rob, I read Peter's blog for a long time, before I realized the effect on ketosis on me. He's very thorough.
Seems he has changed his thinking about ketosis, according to the last paragraph of that post.



Hi Arlene, how many carbs are too many for you? For me, much over 90 grams a day stops me losing for sure, especially if I just sit around... keeping active burns it up.


As for getting into "good ketosis," that's where I part ways. I don't ~want~ to be in long-term ketosis, and lose better without it, maybe because other things, it raises my cortisol which inhibits weight loss.

A year of IF and water fasting has cured hunger pangs and cravings for me. I don't get them anymore, and that's a miracle.


Short-term ketosis for me is a 2-3 day water or fat fast. Last summer I tried a 5-day fast and became quite depressed, though physically, I was fine with no hunger and plenty of energy. I cut back to a 2-3 day water or fat fast once or twice a week and 22-hour IF on the other days, with relatively lenient eating... and still lost very well last summer, better than I ever did on LC or KD.

BTW, more carbs doesn't mean high carbs. It means that I have climbed Atkins' Carb Ladder. My avg carb count is around 70g, mostly from yogurt, carby or starchy vegs at night, occasional fruit for dessert, a light sprinkle of sugar now and then instead of AS. Once or twice a month, a 2-oz bag of popcorn or chips for a treat. And I'm still losing, even with a more lenient IF (16-18 hrs) and more calories... and no depression.


Ketosis-depression happens a LOT, from all the comments here: http://www.paleohacks.com/low-carb/...-low-carb-16375

Emily Dean's post is interesting... too bad she's stopped blogging: http://evolutionarypsychiatry.blogs...tion-after.html

From both these posts and their comments, it's pretty clear that while a lot of people thrive on KD, perhaps just as many don't do well on long-term ketosis.

The Attia article is from July 2013. I believe he has parted from NuSi and started a specialized medical practice in CA.

The last paragraph from Peter's article:

Yes, I read Peter's blog when it was written.

I am not in ketosis to lose weight anymore. I am stable. My intake of meat and fats, I add fat sometimes, is balanced with my expenditure now. I am in ketosis so my diabetes is gone. Like Peter also says, being in ketosis does not mean weight will be lost. A body can gain weight while in ketosis. Eat more fat than you need energy wise and a body will gain weight.

When I am in deep ketosis, and that is most of the time, I have less than 30 (usually many less) carbs. I do go over sometimes when we eat out at nice restaurants or maybe a special occasion or if I am traveling. I have to be careful though as I get bad leg cramps at night when I do, sometimes.

I could experiment and see at what level my diabetes will come back, but that is just not worth it.

Jenny, the first link did not work for me. On the second one, I wonder if this is what we call a "sugar rush" that we blame for our kids supposedly get rowdy after eating candy. Maybe they are just happy!

Thanks, Janet. I just realized Attia's blog post was from July 2013 when I read it again and recalled reading it a few years ago. Note that he refers to Kevin Hall in this particular post from 2013. In one of his recent posts from this year (2016), he mentions his departure from NuSI.

Hmmm, it worked yesterday. Maybe paleohacks' server is down for upgrades or something.


Well, sure kids are happy after eating a wad of candy, I always was.

Serotonin is likely why kids (and adults) crave sugar/carbs... it's in our evolution. More Than Honey is a great documentary on honey bees. One section showed how humans have collaborated with wild African birds called Honey Guides for many generations to find honey combs, a vital source of calories for both birds and humans. One scene shows a Hadza tracker calling and following a Honey Guide, then climbing the tree and gobbling honey in bliss, before passing down the rest. Here's an article about these trackers: How humans and wild birds collaborate to get precious resources of honey and wax: http://www.cam.ac.uk/research/news/...f-honey-and-wax


Nevertheless, I completely agree that lots of sugar, honey and high-carb meals-- or anything that drives up blood sugar to the point where it takes more than two hours to return to baseline-- are bad.

50-60 grams of carbs is my daily average, unless I'm "feasting." Dr. Fung makes a good point about feasts and fasts being part of human history: https://intensivedietarymanagement....asting-part-11/