THEN- my carb flu was an entire year ago, but here goes: I had the WORST feelings of hunger that I have ever had in my life. I felt like I could literally go to a rock on the beach and tear the seaweed off with my bare teeth and eat it all! I felt like I could eat tablecloths, my neighbor, my hand, ...ANYTHING! Without grains, I experienced incredible hunger, even though I was eating paleo food and getting sufficient calories/nutrition. It took about four months for to adapt, and the first month or so were very difficult. The psychological difficulty was in feeling like I was in some sort of food free fall, and it has taken quite some time to trust this way of eating and living.

NOW- missing a meal is easy, I have MUCH better sustained energy, and I don't get nervous about not eating nor do I get horribly hungry.

Going Paleo/primal is one of the nicest things I have ever done for myself in my life. Well worth the effort, funny looks from the family, and transition time.

oh i hated that low carb flu. i dove in both feet, and for the first week i was ok. my girlfriend was doing it with me, so i had her for support. i was also having a hard time with the "eat more fat" thing, and she was good about encouraging me along those lines. i would say it was in my second week that i started to feel really tired- i mean BONE tired. my muscles were so sore and i wasnt recovering from resistance training workouts at all. then, i got a scratchy throat way in back and up, like where strep starts, so thats what i thought i was getting. i took a week off of working out thinking i was getting the flu. i had a TERRIBLE headache that lasted for a few days and that wouldnt respond to NSAIDs ot tylenol. i pretty much spent two days in bed, flanked on either side by two very unproductive and whiny days. i had a ton of mucus, too and was blowing my nose like i had a cold the whole time. oh, and i couldnt think straight. it was like my brain was full of concrete.

then, one morning it all just lifted and was replaced by this wonderful feeling- like energy that you know is clean and natural, not artificial like from caffeine. the first time it happened, i blamed it on some viral infection and couldnt figure out why i was the only one in my family who got sick. those first couple of months though through the holidays, i had a few REALLY non-paleo days, and realized that about two days after a big cheat, i would get that flu again. i eventually put two and two together- it was never as bad as when i first went through it, but i definitely notice than whenever i binge on sugar and carbs, i can plan on that headache, fatigue, sore throat, runny nose, and muscle stiffness a few days later.

For the first 2 weeks I had diarrhea, new acne on my face and body, and a short temper, which I attribute in part to sudden increases in testosterone from strength training.

It was worth it because along with no longer having these problems, I now experience less razor burn, am no longer hungry all the time, my fat is disappearing as my lean body mass increases (less gut and neck fat, more muscle), and, most importantly, I am never sick, not even once since beginning, despite spending about half of the previous 4 winters sick in bed (I was in bed with the flu for 17 days last year!). So, to all of you newbies, hang in there because the benefits are HUGE!

Headaches, tired, drastically reduced weight load/slower recovery from workouts. Oh, and the dead racoon in my mouth...

I was never "high carb" and I am currently not "low carb". Paleo means a lot of things to me, like healthy meat, fish and vegetables, but it does not need to be low carb. I always had and still have tubers. Then of course I never had that flu.

Nausea, the shakes, headache, chills/heat flashes the first full day. I did eventually cave that evening and had a banana to moderate things as I had a nursing infant and 3-year-old in my care. By the next morning I was home free and even a coconut cream pie brought by my mother-in-law didn't seem so tempting all of a sudden.

I'm not sure I understand why people don't gradually step down their carb intake and avoid these symptoms...is there a benefit to cutting it all down at once?

I only got through by drinking heaps of diet colas. Not ideal, but there you are. Three weeks later I had the challenge of giving up caffeine, which was painful.

I never got the 'carb flu' when I was switching to Paleo, I had already gone through the metabolic shifts through IF.... read on to see what I mean.

I did serious intermittent fasting (eating omnivore, mostly from local farmers (but still eating grains and cheap dairy) far about 4 years before I went to a PrimalBlueprint / Paleo / PaNu way of eating.

Back then, I had a really rough 2 weeks of adjustment to IF. The first week or so I was following the adaption suggestions in the Fast5 free eBook, slowly moving the 5-hour eating window further back into the evening. About 1 week in I 'suddenly' did not feel like I HAD TO EAT NOW, and waited until the next morning to eat. The next morning, I lept out of bed and ate an entire 4 person salad and 4 fried eggs. (Heh, in 20/20 retrospect that might have been my secret first step onto the paleo path.)

During the rough 2 week period, I had wicked headaches, malaise, odd energy dips, and some acne. Then I jumped to feeling amazing!!! My weight started falling off, and new muscle galore was mine. Here are some supporting pics as evidence: http://paleohacks.com/questions/7058/share-your-paleo-before-and-after/17739#17739

YAY!

After about 3-4 of IF years I hit a fat-loss plateau, and when I went looking on the web for more variations on IF (which had worked so well for me) I found Mark Sisson's website, was !inspired! and dropped most sugars and grains. This let me drop 21lbs and 4% bodyfat and feel EVEN BETTER.

All of the above was my background for why I did not get any carb-flu when I went paleo... I had already activated my fat-using metabolic pathways through IF, and had 'paid the price' then.

Now, I've got better composition than I have ever had in my life, and I've just gone back to strict IF/EOD this week. This is a fasting day, today, and I shan't be consuming any calories till tomorrow. My EOD Fasting = no calories on Sunday, Tuesday, and Thursday. I make sure to eat to satiation on the other Feasting days.

Maybe this will help me to my springtime goal of seeing my abs for the first time since I was in my teens.

My abs are getting nearer, I can see the outline of them, but not the creases.

I didnt want to drag my butt out of bed and i have a family to take care of and work nights...then after that wore off i felt much better but about 2 months later i experienced it again. i think that may have been TOO low carb...I seem to do better on 50 -60 carbs a day...energy and mental state wize.

My husband and I are currently on our 7th day of the 21 day transformation. We both feel horrible right now, headache, scratchy throat, runny nose and the brain fog and lethargy. I know it will go away soon but it's super not fun at the moment.

I am currently experiencing the Carb Flu. I went gluten free, but not grain free 3 weeks ago and was totally exhausted. I am a rock climber but I spent more time looking at the routes than anything else, just no energy. Then my doctor recommended (yes a MD!!) that I try Paleo.

Well, Mon-Wed were bad as far as mental fog, everything seemed like it was part of a dream. Then Thursday about 4pm the flu hit me hard - I was freezing, shivering all wrapped up in a blanket sitting outside (In ARIZONA - 109 degrees). My body felts like I was hit by a semi-truck, so achy it hurt to walk. Bad, pounding headache too. My roommate thought I was dying and I kinda felt like it. It was all I could do to go to bed. This morning was a little better but I am still a little achy and have had a headache all day. I really hope this helps because going through this for nothing would be awful (and I really want a donut haha).

I actually couldn't tell the difference. I had been moderate carb/high protein/high fiber for a long time though, so it wasn't a huge shift other than the fiber thing. The mental shift to higher fat and dropping my carbs down to around 75 grams (from around 150) was much harder for me.

It was day 3 or day 4 when it started and it lasted for about 4 or 5 days. Just felt like the flu - achy muscles, mucus, lethargy, fogginess.

I didn't get it, but my transition was pretty gradual in retrospect. I had already been off grains for a while trying to maximize nutrient density, and in the beginning my paleo had quite a bit of apples and almonds and such, and probably wasn't very low carb.

That being said, I don't react to most foods or changes in diet. I can eat gluten or sugar and only feel a bit tired if I eat too much. I don't do this though, ever, for obvious reasons. I guess I'm just young and can tolerate it?

Sounds like a low carb slur

Six days into paleo so far. Needless to say. Not feeling very well. Between the sugar withdrawl the complete lack of energy and the diarrhea, I am not enjoying myself so far. Trying to focus on the light at the end of the tunnel. I'm doing this mainly to boost my energy levels and to maybe clear the mental fog wrapped around my brain. Though admittedly I've read of others who did not experience that magical upswing in energy 2-6 weeks into the diet. But I am cautiously optimistic.

As far as the diarrhea is concerned, I'm trying to boost my fiber intake to 20-30g a day (By adding broccoli, brussel sprouts and kale to my diet) so we'll see how that goes. Maybe I've yet to hit some sort of magical number.

I did not go through the so-called flu as many apparently have but I did survive an 18-hour killer headache. Holy moly. I attribute the headache to withdrawals much like a drug addict foregoing his poison of choice. (No way I can be convinced refined carbohydrates are not addictive.) For about two weeks afterwards a very light, way-in-the-background headache would come and go. Once those odd headaches disappeared, I haven't been troubled.

welp. i'm on day 10 of my whole 30 challenge. days 1-9 i felt pretty good. today, CRAP. dizziness, nausea, and dead tired.

this may be due to a particularly heavy met-con yesterday though. trying to power through it.

Ok so I had been feeling pretty bad the last couple weeks and with all the symptoms discribed in this post about LC flu and others I am pretty sure I was/am experiencing it. I have eaten Paleo for a while now with slips, falls and what not but about 2 months ago decided I was done jumping on and off the wagon. About 3 weeks ago I decided to throw some IF in there too and go VLC to get real lean. Well this is my first experience with VLC. I was feeling groggy, angry, tired at times when I should be, headaches pro-longed soreness from workouts. Today was the first day in a couple weeks I have felt back to normal(fingers crossed it stays). I did not fast this morning but I have stayed VLC. Hope this "flu" is over with and I start to truly experience this "fat-burning" metabolism that we all want.

It lasted about a week for me. I compare it to waking up with a mild hangover. Slight headache, no energy, and a bit of brain fog. It felt very strange to have those symptoms without drinking a drop of alcohol. Of course, there were sugar cravings, but those passed within a couple of days. From what I gather, there is a broad range of experience here, so there's no predicting how easy it will be, although eating more fat may shorten its duration/severity.

Understanding the biochemistry that is going on helped keep me motivated because it suggests that the symptoms are a sign of positive change in the body. Stick with it!

If it's unbearable, have a piece of fruit or don't bother going low-carb at all. If you don't need to lose a lot of weight or reestablish a healthy metabolism, it may not be necessary. Try the Perfect Health Diet if low-carb isn't for you.

If I had any adjustment problems, the symptoms were masked by other problems at the time, so it seems like it was all just effortless for me. I read Taubes, it struck a chord, set off chimes, and so I went paleo as if my life depended on it. Well, it DID depend on it. That too makes the transition bearable I suppose. I just can't remember anything to blame on paleo, except maybe cutting out fiber, but that's going beyond paleo, isn't it?

I am going thru it right now. Only been primal for 12 days. The first week I was starving all the time but was eating appropriately. Then after my body got rid of the the last of the carbs in my system at day 4-5 I stopped being able to sleep. It have been a week of torture! No sleep and tossing and turning for hrs. But I am sticking with it and understand why my body is doing it. I contacted my doctor to get a sleep aid and am hoping it will help take the edge off. My fuzzy brain will be thanking me once I get at least 5 hrs. of real sleep. I also have not lost any weight once I stopped sleeping due to my body chemistry being so out of whack. :( But I have faith and know this is the lefstyle for me. I hope the flu doesn't last months like some people have stated. But will take it one day at a time.

MJ-

I am now ten weeks into Crossfit and Paleo at about 90% (As an Asian, giving up white rice is proving difficult, to say the least).

This week, I could barely finish the WODs. I have a swollen lymph node in my neck.

My endurance and strength are at a low point since I began Xfit and Paleo.

Grogginess, short temper, difficulty falling asleep (although sleeping well when I finally do).

I think I have the Paleo flu with an additional dose of Xfit overtraining.

I intend to cut WODs to three days a week and give myself time to adjust to the new diet and lifestyle.

If the swollen lymph node doesn't take care of itself, I'll gouge it out with a dirty stick like the caveman I am. :)

One thing I have not heard a single person talk about is upset stomach and cramps. I started paleo about 7 days ago and for the last couple of days I have been in agony. If my stomach doesn't feel like I've swallowed a brick, I am rolling on the floor because my stomach hurts so badly. Is this something associated with the transition into paleo? I'm about the bag the whole process because I really think there is something harmful going on inside of my body from the amount of pain I am in. I am drinking 8 or more glasses of water a day and following Robb Wolf's paleo meal plan, I don't know what is going on!

But other than that, headache- yep!, can't sleep- yep! I'm following Robb Wolf's meal plan though, so I don't know how to make it any better since I assume this is the ideal way to go paleo?

Hi I have been on the Paleo Diet for 4 days - lost 6lbs and totally exhausted! How long will this last?

What's weird is I started my vegan to paleo transition about two months ago, first 5 weeks I felt AWESOME and people even were commenting on how I looked much better, etc. I went from eating literally almost only fruit to high fat & protein and below 50g of carb a day. Then, I fell off the wagon heavily for a weekend, equipped with ice cream and cake and I've been struggling ever since then. Fighting off (or not) old binging habits, feeling exhausted, groggy, cranky, etc. Still maintaining low carb/high fat though, it's just way more difficult.. I don't know what happened but I'd like to return to feeling like a super hero plz.

Well I don't know if it's Paleo Flu but I'm on day 7 and for the first several days I wasn't sleeping well at all but I'm better the past two days. Kind of have some diarrhea and just no muscle energy all week (going up a slight incline or stairs just is so HARD). Also I seem to have some neck and back aches, more joint pain. Missed two Crossfit workouts because I just had to catch up on sleep and was so achey. I still did two whey protein shakes and a decent amount of green peas this week, so I'm not even sure if you could say I went totally Paleo, but no dairy and no bread at all. Some of this could also be from hormone fluctuation, too. I did eat plenty of fruit, and had some chocolate almond milk for a snack/treat. I guess that counts? I'm not counting carbs at all, just trying to stick to the food groups. Really want to do this for a minimum of 30 days and see what happens. Loving my frittatas and carnitas salad with guac. mmmmmmmm. Also made Zoodles with meat sauce - julienned zucchini noodles! So yum...

I felt like I was going through drug withdrawal for three weeks. I needed a sponsor, a meeting. Exhausted, craving, just laid out. Once three weeks and reaching 65% fat in my diet did I come out of it. It was rough.

I SOMEHOW MANAGED TO CATCH REAL FLU INSTEAD OF CARB FLU!

Cut down to ketogenic levels on the saturday - started to feel a bit achey and foggy on the tuesday - Took Wednesday off work as I was feeling awful (aches,hot,shivering,headache) ended up taking pain killers. I kept on looking online for any other experiences of carb flu this bad. It was only on the friday that I accepted that I did indeed have influenza (Man flu). It took me a week to get back to work.

DOH!