Hi, JeiCR. I am a doctor, and that really does sound strange! Do you think extra sodium could have been sneaking into your diet, such as in soups? Or a lot of extra caffeine? Were you taking a decongestant medication, by any chance, or any weight loss supplements that could contain stimulants? Are your ankles swelling a lot, in which case you would need to get your kidneys checked? (I know you said nothing else had changed, but just checking.)

What is your current BMI? Could it be that you are stressing your body by trying to force it too low (although I don’t think I have ever heard of such a thing)?

If your BMI is well within the normal range, maybe you could maintain your loss just by training for the 5K, or by fasting only 6:1.

JelCR, getting a complete checkup does sound like a good idea just to rule anything else out, as I haven’t heard of this before even though quite a number of people have been in research studies involving alternate-day fasting.

However, it is possible, since fasting can raise levels of epinephrine and norepinephrine. Most peoples’ systems adjust, but maybe yours is extra-sensitive.

Is your pressure back to normal off of 5:2 and off medication, or do you need to stay on medication to keep it down? If you have to stay on medication to keep it down, I would suspect a cause other than fasting; the rise in epi/norepi goes away quickly when you stop fasting. However, most high blood pressure is “essential”, meaning they are not able to figure out what the cause of it is.

A relatively rare cause of very high blood pressure is narrowing of the arteries in the kidneys. This can be caused by high cholesterol OR by other things, like a condition called fibromuscular dysplasia that causes smooth muscle cells in the arterial walls to over-proliferate. If the arteries to the kidneys are partially blocked, they think the whole body is in shock and pump out a bunch of hormones to raise the blood pressure to compensate. I had to have an angioplasty of my renal arteries at age 43 because of this, and my blood pressure is still quite sensitive to sodium intake. However, if this is the problem, eventually medication will not control the high blood pressure, and then there are tests that can be done to see if this is what the problem is.

So, I started the 5:2 diet when the program was first broadcast in the UK, and managed to get my weight back to normal. For clarity, I’m 53, I exercised a lot, this was that final 12 pounds around the waist that refused to shift.
Anyway, at the time I started I had a full medical and my BP was normal.

I’ve kept the 5:2 going, twice a week when required and once as my weight leveled off, and I can say that I’ve really felt healthier over that time frame

16 months later, I’m training for a run and they offer a BP test. I’m sky high!
So now I’m on BP tablets and trying to get this under control.

I can’t point the finger at 5:2, but it’s the only thing that has changed over those 2 years and my blood result show every other factor as fine.

Now it might be age related……but I’m no doctor!

I must also report that sadly this diet caused my blood pressure to become high (150/95) – within two weeks of stopping the diet it returned to a normal (113/75). I was on the 5:2 for just over two months and successfully managed to loose 5 pounds (I do not have much weight to loose).

I found the diet easy to follow and ate healthy options for my 500 calories on fast days – I did not increase my salt intake as someone previously suggested in this topic. I started to feel a bit fuzzy headed and a bizarre feeling as though I could feel my blood being pumped around my body. A routine doctor’s appointment picked up by elevated blood pressure which had previously always been normal. It was also checked several times over different times and days. The only change in my routine had been the start and continuation of this diet which I promptly stopped at the recommendation of the doctor. As mentioned, two weeks later blood pressure back to normal.

A lot more scientific research needs to be done to further test and analyse this diet – be very cautious people and check your blood pressure if you are on this diet.

I had my old pressure checked yesterday at 2 pm after fasting. It was considerably higher than usual, but not a bad thing for me as it was always too low. And I had a ton of energy.

Also had an audience telling all the ladies at the des office about IF. Spreading the word!

I have been on the diet for about 2 years. I went to the doctor today and for the first time in my life I have high blood pressure. It has always been low. As the only thing I have done differently is the diet, I am very concerned. Like some of the other posters I have a healthy lifestyle and the diet is the only change.

This is very interesting reading. Thank you all for posting.

I have always had borderline high BP readings. From the age of 50 I have been on BP meds. Slowly I gained weight and my BP meds needed to be increased. 18 months ago I began on 5:2 where I gave up wheat, and all other starches and sugars while losing 17 kg (37 lb) over six months.

I have maintained this weight loss for 12 months, with one serious fast a week, plus a lighter eating day. And I keep an eye on my sugar intake.

My BP meds were reduced by one third as the weight came off. However, one year later my BP went borderline high again. My doctor wanted to increase my meds, as I would wake up with high BP.

Instead I began taking my BP meds at night. This means I sleep better, and wake up in the normal range of BP. I stress that this is an experiment of one. And I am not a medico. And I do not give advice to others. Just recording what I am doing. I love my serious fast day, usually a Monday as it resets my calorie intake levels, and gives me a feeling of clean energy.

If after a while this method of taking BP meds stops being effective, I will need to think how to handle my BP from here on. In the meantime I think it helps to read of others experience and compare.

Cheers, Bay 🙂

Two weeks is up and … surprise, surprise…after monitoring my bp very carefully, at least 3 times a day, I can see that my bp is elevated most of the time. Back to the doctor to include diuretics in my meds again.

Looking at the data, there is no obvious connection, over two weeks, between fasting and elevated blood pressure. Nor is there a connection with exercise or alcohol consumed. Time of day is the most obvious variable.

I will continue to fast and will adjust the medications. Hypertension needs to be taken seriously …. it is the “silent killer”….but fasting has so many life benefits for me, and I cannot find a link between the two.

Anyone else tried this experiment? PVE

I decided to stop the diet after seeing the rise in my blood pressure. The 5×2 was the only change and I exercise and eat very healthily. Ironically my cholesterol had dropped after 2 years of the diet. Now I am wondering if fasting for just one day would still raise the blood pressure.

Hi all,

I have been doing intermittent fasting for over 10 years now long before Michael Mosley made it fashionable and it is one of those things that I will do for a few months and then gradually life gets in the way and then I forget about it for little while but always to return at a later date. I’ve noticed that my body seems to have a sweet spot above 12 stone whereby I will generally feel worse and get symptoms of inflammation such as arthritis in my fingers etc. Just lately after not going up the gym for a while And putting on a little bit of weight taking the above the 12 stone mark.I decided to start doing intermittent fasting again. And straight away I noticed that my blood pressure started shooting up.I have noticed this before to a lesser extent And I hadn’t tied it to the fact that I was intermittent fasting. I can normally keep it below 120/80 but for the last few weeks it has been hovering around 140/90. I have a couple of home blood pressure testers so I am able to frequently check. This was concerning me since the whole point of doing intermittent fasting is to improve my health. I think I must have gone to bed sleeping about this because the couple of days ago I woke up and thought maybe when I intermittently fast I am not getting enough liquid. I know that when you are in ketosis your body needs a lot more liquid than when you are not in ketosis. I decided to drink an extra four or 5 pints of water per day. And what a difference this has made. I have just tested my blood pressure and it is 115/71 and that is after finishing a 48 hour fast yesterday evening. I would be interested in feedback from other people to see if increasing your fluid intake (not tea or coffee) has the same positive effect that it has done for me.
Andy

I haven’t had time to look at any studies (because I’m in the pub) but I just saw a snippet in the paper that says research suggests that vitamin D supplements can reduce blood pressure and stress hormones.

Whoops! Just reading, didn’t mean to post 🙂

Hi there

I said I would post again after some time of taking BP meds at night. I can report that I am still on the reduced BP meds and I am still taking them at night. No diuretic. This is working for me. My BP is in healthy range. I have to drink a minimum of 2 litres of water each fast day. I have been doing 5:2 for 21 months and have maintained the 15 kg weight loss. Dehydration definitely affects BP.

Cheers, Bay 🙂

I am intrigued by the point about fasting and high BP.

My background: I didn’t normally have a high BP, except it spiked sometimes for no reason that I or the doctor could fathom. A very long time ago, I was put on BP lowering drugs, but then my BP dropped so much that I was taken off, and I kept an eye on it over the years.

I previously lost weight on the 5:2 – I didn’t monitor my BP because it wasn’t relevant. I lapsed and put weight back on – overweight, but not obese.

Last spring, I was in hospital with a diagnosed kidney stone. When I was vomiting and in pain from it, my BP soared. I understand that, and I must have been dehydrated. But then the stone stopped moving and I was given pain relief, no more pain and my BP dropped. Then I was on a drip but nil by mouth for a procedure – still no pain – but it soared again.

This happened again two months later when I went back to have the stone removed. My BP wasn’t too bad when I was checked pre-op, but when I was nil by mouth but on a drip for a full 24 hours, my BP soared again. I never understood this, I wasn’t particularly anxious, rather drowsy.

Is nil by mouth on a drip a bit like a starvation day but hydrated? Could my BP have gone up because of the lack of food?

I do have type 2 diabetes, normally under control with Metformin. Curiously my blood sugar level also went up when I was nil by mouth. Now I am back on the 5:2. I will have to check whether the high BP coincides with fast days, even though I stay hydrated. I too don’t want to have to abandon this method of losing weight.

Hi Try,

It may be no coincidence that your blood sugar was elevated. I’m no expert, but there appears to be a link between insulin resistance and hypertension, e.g.

http://www.nature.com/ki/journal/v87/n3/full/ki2014392a.html

I have just checked my BP and it is a ‘Fast’ day for me, the first one in a while. It’s disappointingly high at 160/100 and this is unusual on a day when I have run. I ran 7 miles this morning and on an ‘average’day (non-fasting) my BP is down to 120/80 without my meds after an hour’s running in the morning.

Something definitely upsets my BP on Fast days, so we are not imagining it.

My BP is what is known as ‘labile’. (it goes up and down easily).It can shoot up to 220/115 with white coat syndrome, which is bizarre as I am a nurse myself and really like my GP of 20 years. I wonder whether others with labile BP are affected by fasting more than other hypertensive sufferers?

There are multiple reasons for a raised BP. Another area where we need more research.

Hi,

I logged on to ask a question about 5:2 and BP, as mine has increased lately. I also realised that at the end of the 2 days I felt like my BP was going high and it was. I love the diet.

I’m wondering if it is an adrenal/insulin reaction? If it is maybe small amounts of protein through the day may help. But I also used caffeine in the form of diet coke to help me – I’d have 2 a day on diet days so wonder if this is a factor too.

I’m off it now as it did feel an unhealthy reaction but I’m disappointed as I felt it suited me ie I could actually do it!

I lost 10lb – my weight is 127 lbs but I’d like to get down a little lower

Hi proberts,

Yes mine is definitely labile. I’m going to try small amounts of protein through the day and give up the diet coke and see what happens.

Thanks for all the info on the site.

Hi
Yes I think that the stress of missing a meal can increase blood pressure. My partner recently had raised blood pressure diagnosed following a very stressful six months at work. However, by careful monitoring, a vegetable based diet – especially the leafy green ones, avoiding meat, wine, coffee, chocolate, gentle exercise and not missing meals, his blood pressure is back in the normal range.

I think you have to be healthy to withstand a 5:2 diet – It is probably best for young otherwise fit people. For us older citizens, a more gentle and holistic approach is needed with a focus on health, healthy eating and gentle exercise coming before weight loss. Losing weight quickly means your body has been starved, and although occasional starving is not as bad as people might have thought, too much may well cause problems.

Losing weight is a stressful activity, because however you dress it up, it is starvation! and that is stressful for a body more used to a dinner and two couches lifestyle. Stress,both physical and mental stress increase blood pressure, short term and long term. This does not mean we should avoid stress, rather that we need to be healthy enough to cope with it.

Apologies for the delay in replying – email problems (don’t ask 😉

i agree – i think that everyone’s physiology is an individual affair and that different things are good for different people
There are a number of simple physiological processes that people can check themselves that are relevant to blood pressure
– first of all, blood pressure varies from moment to moment and hour to hour – and managing it is an individual process – for example, stress in a relationship or work or other area can cause a rise in blood pressure and only by close monitoring can anyone have a hope of working out what personal triggers are
– secondly there are a number of physiological measures that we should be all be familiar with, and which interact with blood pressure, these are blood sugar – blood sugar monitors can be bought on amazon for not a lot of money. A rising blood sugar, or increasing insulin sensitivity can be associated with rising blood pressure. Also, cortisol levels – there are companies offering salivary cortisol (biolabs – are probably best value) can provide a sensitive measure of physiological stress – too much cortisol will almost certainly lead to a rise in blood pressure. In your case where there is no obvious answer with respect of health, measuring blood sugars, and cortisol would provide some useful information in relation to your blood pressure would be helpful if your wanted to look at what was causing your rise in blood pressure.

You might also want to look at your urine pH to see whether you are in acid – base balance. Too much acid, means your body needs more green veggies to balance your pH

Also keeping an eye on percentage body fat rather than weight gives a more accurate estimate of the extent to which someone might need to diet.

Finally, in an otherwise healthy person carrying a little extra fat, is not necessarily that bad, especially if it is on the limbs rather than round the waist may not be too bad in terms of health

I think your approach of closely monitoring your bp and seeing what happens to your bp is fascinating – keep us posted!

Yes – I agree it would be useful to have Michael Moseley comment would be helpful – however he is doctor journalist as much as a doctor practitioner – maybe there are some other GPs out there who would like to comment on their experience of patients who have used this approach

Finally – one size doesn’t fit all – we have to work with our own physiology for what works best for us -congrats on what sounds like an overall healthy lifestyle. To be honest, as doctors we know too little about healthy physiology on a day to day basis – and this is where research money might perhaps be more usefully spent because they are aspects of life that affect us all

Interesting. Most of the research out there correlates fasting with reduced BP.

You can get blood sugar monitors either from your local chemist or online, the test strips tend to be a lot cheaper on line – I use once called True which has the cheapest strips

Adrenaline is difficult to measure because it doesn’t stay long in the blood – less than a minute I think
Cortisol levels are now widely available – Biolabs do them from saliva and recommend a profile over the day – personally I think that you need a profile from more than one day, coupled a diary records, blood sugars and blood pressures to get the most useful info – because everything interacts (no surprises there!) it might for example be interesting to do a profile on a fasting day, a non fasting day and the day after fasting

I am hoping to start the group in the summer – based in Fulham and will post here if I may with contact details to see if anyone is interested in joining the group – self financed with results on the website –