Just want to contribute that when I started this plan, I was getting quite severe headaches the day after fast, until I significantly increased water intake. Found I had to drink at least double my usual intake to eliminate headaches – but it worked. No headaches at all since then. Had no idea I was dehydrated. Good to know.

For me, one of the best buffers to prevent migraines are freshly made vegetable and fruit juices, which I make in a juicer. Ever since I started to make these on a (ideally) daily basis I have experienced a noticeable reduction in the frequency and severity of my migraines. I have even been able to stop mild migraine attacks by simply making a glass of veggie juice. It takes about 3 hours for my head to get clear again, and the best part of it is, no pain killers needed! This is quite phenomenal considering I’ve had migraines all my life. Of course, as we all know, some days nothing will stop the oncoming freight train.
I haven’t been on the fast diet long, and so far I’ve had only one severe migraine attack on a fast day. The day before we were celebrating a birthday in the family, and I was dehydrated from a combination of coffee and alcohol and hadn’t offset with sufficient water.
As a rule I do have a light migraine after the second fast day.
Unfortunately there are so many migraine triggers and how these play out is highly individual. I do keep a migraine log just to keep tabs on my triggers, and I have recently restructured it to include the variable of fast days. Hopefully I’ll be able to discern a pattern and then work towards preventive measures.

I had a pretty bad headache the first month but since I almost doubled my water intake, take some bouillon at lunch time and have some low GI fruit in the afternoon, I’ve been fine.

One thought for some – do you normally have caffeine on non-fast days, that you are not having on fast days? Some headaches could be caused by caffeine withdrawal if so. That, and dehydration.

Thanks all, I’ll try to drink more water on fast days (my caffeine intake is the same on every day as I only drink a couple of black coffees a day 7 days a week).

I have been doing the diet for 5 weeks and seem to suffer from headaches on the day after the fast. I still have caffeine on my fast day and try to keep the water intake up. I do have a sweet tooth and wonder if it could be sugar withdrawal.

I have been on the fast diet since the beginning of the year and used to get headaches on my fast days, normally by the afternoon/evening time. Mine couldn’t have been caused by lack of water as I was drinking so much to get me through hungry times, but I read somewhere that you can get headaches by drinking too much as you are diluting the sugars and salts your body needs and that this can cause headaches (am no medical expert so am happy to be corrected about this). I used to take a couple of paracetamol which would sort them out (lucky for me have never had a migraine) but I no longer get these headaches so perhaps by persevering your body adapts? Have gone from an overweight BMI to a healthy (lost a total of 22lbs!) am feeling great, looking well and enjoying all the positive comments I receive 🙂 am happy to continue with this lifestyle, may drop a couple of fast days a month once I reached my target weight but can’t see me not keeping fasting as part of my lifestyle from now on.

I’ve tried something new the past couple of weeks and it seems to be helping. Just simply adding salt on my fast day. I don’t know enough about sodium deficiency to know whether it can cause headaches after just one day of low salt intake, but I realised that on my fast days I was consuming little to no salt. I’ve just made a conscious effort to add salt to the little food I eat on a fast day and so far no bad headaches. But it’s a little early to proclaim a miracle cure.

Like most of us I’ve come to regard salt as an unhealthy food which must be eliminated as far as possible but it’s possible that on fast days we need to make sure we get some of the white stuff. I’ll carry on with my one man experiment and if my headaches stay away I’ll let you know.

2nd day of fasting for the week. My headache is dulled but still there. I went to bed a bit early, without taking anything and this morning it was better (but still there). I am eating my first meal of the day (oatmeal and chai tea) and seem to be doing a bit better.

I have only just started the 5:2 diet and yes the headaches came along. The morning after the first day and then lunchtime of the second day right through ’til the evening. I am going to double my water intake next week and hope to eliminate the dreaded headache. Will keep you posted. Fingers crossed.

Newbie suffering headaches. I started fasting last week; I did Wed and Friday and although I can already see a difference in my clothes, I have had a headache since Friday and a horrible bloated feeling in my abdomen and chest. I’ve read the comments above and am slightly reassured that the headaches will pass as I get used to this way of eating. I will be fasting tomorrow therefore I’ve eaten my last meal today (7pm) and will not eat again until 7pm tomorrow (500 cals) and then next meal on my non fast day Tuesday at around 10/11am. I never suffer from headaches and was interested in the comment about too much water consumption. I am wondering if maybe I’m overdoing the water dose as I never normally drink water but usually drink lots of coffee? in addition I’m not sleeping at all! anyone else feel like this? Will it pass?

Thanks Annette. I have started my second week, fasted yesterday. I still have a headache and although I’ve cut down coffee consumption most days have decided to go back to having my morning coffee with milk, everyday. I’m hoping the headaches will subside! Any advice would be great.

As a migraine sufferer I usually have good results with Magnesium.
In the middle of a migraine I take 3 times a daily dose in one (overdose magnesium can cause diarea, thats about it).
For maintenance just normal dose daily.

I had forgotten to take the tabs. for a while.

When starting 5:2, I got headaches on fastdays, despite drinking lots and I also became constipated.
Starting the daily Magnesium seemed to have solved both problems for me.

I am a regular migraine sufferer and sometimes I get headaches on or after fast days but then I get up to 3 migraines a week anyway… I know that any change to your lifestyle can trigger migraines (in those susceptible) due to stress hormones. So this may be caused be difference in sugar levels, sleep patterns, exercising more or less, whether your more or less stressed during these days etc.

I’m now into week three and the headaches have finally gone, just as many have advised. I’m guessing it was my bodies response to the diet. Thanks for the tips everyone, I’ve made a note just in case they reoccur.

Just popped out to buy some fresh coconut water from Waitrose as need to hydrate fast today, have trouble drinking lots of water, and after a small glass am already starting to feel abit better from mild migraine. Am drinking Vita Coco natural coconut water with orange. Says it’s “bursting with electrolytes, more potassium than a banana – potassium helps keep body properly hydrated. No fat or cholesterol” Also gluten and dairy free.

Since I have changed my diet and the type of foods I was consuming I have dropped my weight by 25 pounds. I taken up long walks daily for exercise drink lots more water and my headaches have gone away.

Did a reduction in my blood pressure relieve the headaches as a result of daily walks with increased water consumption as I take a bottle of water with me each day. Dehydration brings on headaches. Did taking out a large portion of sugar out of my diet help?. Did the introduction of more fresh fruit and raw vegetables reduce the headaches. Did taking out the processed foods and their additives especially peanut butter help? I am eating real food now. I do eat rolled oats regularly and pasta as well as bread a couple times a week so I know it is not the new fad scare of gluten in the diet.

I have suffered migraines on and off in the past but it has been a while since I have had one. I have only had one headache in the last few months and it was relieved by drinking more water.

I’m a newbie at the end of my second fast day. I don’t normally get headaches but have one that came on this evening after my light omelette dinner and is still bothering me now. I reckon I’m hydrated enough but it’s been good to read through this as see some of the suggestions. Thinking it would be good to have a list of these somewhere…in the meantime here’s a list of suggestions for the next reader:

-eat a bowl of muesli in the evening before a Fast Day
-increase water intake
-drink a glass fruit/vegetable juice
-Bouillon for lunch and low GI fruit in the afternoon on Fast Day
-drink mineral water on FDs
-add salt to food on FDs
-Include carbohydrates in dinner before FD
-Take magnesium supplement on FD
-Drink coconut water on FD for extra hydration
-Tea drinkers have your tea on FDs

I hope this list is useful for someone. I’ll certainly try some of these suggestions

I have been having daily pressure headaches since I started the diet in January. I have good hydration but have reduced tea drinking in preference to herbal/fruit teas which I now prefer.
I will try the muesli idea for the next two weeks to test results. I am happy to make my way through the list as an experiment. I will switch my weight watchers low cal soup to chicken noodle which is very salty. I will report back. Good luck to other guinea pigs who are trying to help solve this problem.