This isn’t about getting accidentally kicked out of ketosis. This is about the pros and cons of staying permanently in ketosis, as against intentionally coming out from time to time.
Arguments for and against, please - for people who are T2D/metabolically deranged, rather than your healthy body builder types who use keto purely to lose weight.
Where does fasting fit?
Fasting, that is going for time without nutrients, works very well with Keto.
Carbohydrate Cycling, where you cycle from a low carbohydrate diet to a moderate carbohydrate diet has particular problems specifically for people with metabolic derangement. The first is that getting into a ketogenic state takes longer for us.
This korean study that found that ketonuria (ketones in urine) in fasting people is a sign of better metabolic health cited several references that showed that people with metabolic syndrome can take longer to get into ketosis (and when they do they don’t produce as many)
A metabolically healthy person may be able to have a weekly carb up day and be back into ketosis after 3 days of resuming low carb eating. For a person who is metabolically deranged they may not be back into ketosis by the time the next weekly carb-up happens. Remember ketosis means a brain adequately fueled on mostly ketones.
For an insulin sensitive person 1 day of carbs can means 3 days of poorly fueled brain and then 3 days of keto-fueled brain.
For an insulin resistant person 1 day of carbs can means 6 days of poorly fueled brain.
Interesting… the subjects in the trial you cite were all non-diabetic. Overall, though, is your view that we are better doing our best to stay permanently keto?
Maybe I’m weird. Last week I accidentally got out of ketosis - Indian restaurant, my meat and veg choices must have contained carbs I didn’t recognise, because the following morning my ketone meter said 0.0. But, 24 hours later, it said 0.6.
We are all individuals…
I made the mistake of trying “carb cycling”. Big mistake. It erased a lot of hard work I put in.
When doing ketosis for the first time, it will take time first to get into ketosis and my body to get used to it. And then many weeks to become fat adapted. On top of that, the new way of eating, from craving eating carbs to crave eating fats.
When I tested carb cycling, it fucked things up. It erased the fat adaptation, and carb cravings came back. Which means all the hard work I put in was canceled. Had to start over essentially.
It really pisses me off when I see so-called “experts” on online keto groups advising people ( who have clearly stated they are diabetic, or metabolically deranged, or very obese) to do carb cycling, or implement “high carb weekend meal”, and saying asinine things like " it will reboot your metabolism". It’s bro science. And of course, there’s no way to have an intelligent interchange with someone spewing bro-science. They will defend their point with anectodal BS.
I was just thinking about this yesterday. A certain “expert” who promotes carb cycling was working with a medical doctor who claimed that following this carb cycling plan improved health markers for his diabetic patients. I was wondering what happened to him…he was active talking about this in podcasts with the “expert” fitness dude. Haven’t heard or seen anything from the doctor in at least a year or two. (You probably know who I’m thinking of.)
Same experience with me. I went from calorie-restricted to LCHF to carb-cycling and finally to the ketogenic diet and far and away keto is the best of all those experiences.
I do notice on days after I’ve had a bit more carbs that I am hungrier in the morning. Enough to notice, not enough to turn me into a carb-seeking monster. But I think it’s a case of forewarned is forearmed… knowing this can happen, I take the “eat when hungry” motto of keto with a pinch of salt, and stick to my usual no-breakfast routine.
I’m still keto, though - I haven’t done an actual deliberate carb-up, but I guess some days I’m closer to the border than others.
Yep…that’s my experience. If too many carbs gets into my meals, I lose the natural satiety signals. I feel hungry all the time. And it takes many days or weeks (depending on extent of damage) of keto to regain the satiety signals back, and switch from craving carbs food to craving fat food. Today, if I’m hungry, I want to eat butter, boiled eggs, bacon, smoked salmon and fatty cheeses…not cookies.
I was in ill health, significantly overweight, and had eating issues that boredered on addiction when I ate carbs. On a keto diet I am healthier, happier, and 50 pounds lighter.
What is the rational for cycling carbs?
I think there is a huge difference between accidently ingesting an unfamiliar substance in an otherwise keto friendly meal and having an all out carb laden carb cycling event. I can drop out of ketosis from eating just a bit too much protein, But I pop right back again. I haven’t indulged in excessive carbs in many months, the last time wasn’t a pleasant experience and took many days to overcome.
“What is the rationale for cycling carbs?”
That’s what I’d like to know too. So far people have focussed on potential negative effects - though my hunch is that, like so many things, it will vary from person to person how much you experience them. Like keto flu - I really didn’t suffer from it.
No, what I’d like to know is - are there potentially any positive reasons to do it. If the answer is No, that’s fine. I’d just like to know.
And the difference between ripping out accidentally from an unknown ingredient and a full-on 200g carb day (for example)… are you thinking that it would take longer to get back into ketosis after the latter?
Although I can say that carb cycling failed for me, and probably will for anyone with metabolic derangement, the best arguments for it come from John Kiefer in his Carb Nite Solution and Carb Back Loading eBooks, but you can get a sense of his theories from the various podcasts he’s done over the years.
Please note that I am not recommending carb cycling, just pointing to a source that can explain the appeal it has for some people.
Some of the rationale behind cycling is to keep leptin regulated while dieting, but I think that could also be handled by a refeed not specifically carbs?
I’m coming in really late to this. Decided to look into carb cycling cause I keep hearing newer ketoers talking of it. Personally, with all the science I’ve read here, I’m skeptical about the carb cycling but figured I’d at least see if there is any compelling evidence to support it.
I feel my satiety signals have improved, considerably, with Keto and IF/EF. When a carb eater, as many of us experienced, my satiety was non existent. So personal experience tells me fasting would be better for leptin than carb cycling. And, as some people stated above, I’ve noticed I actually feel hunger the morning after some extra carbs. But, I now don’t trust that hunger, like the carbs are lying to me. It seems a bit ironic to me anyway that carb cycling might be thought of as regulating leptin when carbs have always been such a hindrance in this area.
It might be worth looking at the YouTube channel for ketoconnect. They did a month of carb cycling and reported on the results.
I have been eating very low carb for over a decade (carnivore for past 2 years), and during that time, I lost close to 180 lbs and have maintained my loss for 8 years. When I began, I read an article by a physician who claimed to have worked with Dr. Atkins. This guy suggested doing a ‘carb day’ every 6-8 weeks. He explained the science, but I was new to all this at the time and couldn’t follow it. But I took his advice, and exited ketosis with carbs every 6-8 weeks. I had no problems with eating the carbs or stopping after one day. Did it help me? I have no idea, but I didn’t notice any negative effects at all.
Recently, I followed one of Dave Feldman’s protocols for lowering LDL for testing. I am hypothyroid and have labs every 4 months. Recently my endo was ‘making noises’ about my LDL, so I wanted to see whether Dave’s protocol worked. It is his most recent one that involved eating at least 150g of carbs for
3 days prior to the test. I did that (no grains, sugar, etc.–healthy carbs only) and lowered my LDL by 40 points while my high HDL and low trigs remained the same. Dave considered this a success as I did.
So that’s how I ‘carb’ now (next month is next time). I didn’t have any ‘issues’ with those carbs, but by the third day, my appetite was beginning to increase. I had no problem at all returning to my carnivore WOE.
Mark Sisson claims that being able to exit ketosis occasionally and easily return is a good thing, a sign of ‘metabolic flexibility.’ I have no idea whether he is correct or not, but I know that eating carbs (for a good reason and only occasionally) is not a problem for me.
So far, I am always a “carb-seeking monster,” even when fully satiated on lots of lovely fat. While I haven’t yet binged on sugar/jam/doughnuts/bread, I’ve had more (healthier) carbohydrate than is good for me several days in the past few weeks. It’s typical addictive behaviour, like the alcoholic waking up from a blackout after intending not to drink the night before. It may be a long while before it’s safe for me to have any potato, say, or any carbs other than what comes naturally in my meat and dairy or the occasional salad.
I guess for me, zero-carb carb-loading is what works best. 
Thank you. I hadn’t seen this yet. Several interesting take-aways from their experiment. Mostly I find it interesting that they found one day a week to be too much and were speculating that once a month or even longer would be more ideal, if at all. Other than increased gym performance they didn’t have much good to say about it. Interesting too that these are two young insulin sensitive people who struggled to get back into ketosis and by the time they were feeling normal/good again, it was time for the next carb day. Seems to leave a kind of narrow group of ideal people that this might be good for. That gives me some starting knowledge at least. Thanks again. So now I’m left wondering what in the heck the every other day or couple day a week carb cyclers are doing/feeling. Seems to me they’d forever be in adaptation mode. How can that be a good thing.
@Mare Your experience of reading and following a doctors suggestion to carb-up one day every 6-8 weeks is in line with the results of the KetoConnect experiment above where they discovered once a week was too often and monthly or longer would be better. Interesting though you didn’t really notice help or hindrance with it.
I’ve had the thought to possibly follow a Feldman protocol as well. I do worry about it causing some negative reactions as far as carb cravings or just knocking me out of sync since it needs to be 3 full days. Good to hear you made it through, but it sounds like right at the precipice with appetite starting to increase in day 3. This may be the only time and reason I ever do a carb-up or carb cycle.
Thanks for the info.