The FastDay Forum

hi, my partner Clive and I have been on the 5:2 since September and done really well. One thing I've noticed in particular is that I am not experiencing massive crashes in mood and shakiness when hungry. I used to practically have a sign round my neck saying 'stay clear, woman in need of food, about to kick off' and now I can sweetly say 'oh, I feel a bit hungry'. Anyone else noticed this? And can anyone tell me why it's happened

We've done a e-book about our experience, with recipes and tips for everyone. You can find it here (no trousers were harmed in the making of the photograph):

http://www.amazon.co.uk/gp/product/B00A ... r_asin_lnk

keep up the good work, everyone!

I am interested in your comments on your blood sugar. I get severe migraines and if my blood sugar drops then I will get a migraine. I did my first fast day last week and ended up with a migraine, but didn't want to be put off. I fasted again yesterday and when I felt a bit shakey, as if my blood sugar was dropping, in the afternoon I had some semi skimmed milk. I didn't get a migraine so I will carry on and try to adjust and work the fast day calories out to suite me. I think I probably had a little more than 500 but I will get it sorted eventually. Not going to weigh myself just yet though.

[carorees]

Yes, it seems that when we are overweight our bodies find it difficult to release fat from stores to supply energy. Fasting seems to restore the ability to access the fat stores once the body has had a bit of practice!

The more technical answer is that when overweight we may become resistant to growth hormone. Growth hormone as well as being involved in growth as the name suggests, is a key hormone in blood glucose control. It acts in opposition to insulin, so while insulin converts our excess calories to fat, growth hormone converts fat to energy for us to use. Fasting triggers growth hormone release but if we are resistant, the fat is not released properly in response to the growth hormone so we get a blood sugar crash. Weight loss (and it seems fasting) restores the ability to respond to growth hormone and so we don't get the blood sugar dips.

The blood sugar crashes as well as causing mood changes and shakiness seem to cause headaches.


These effects seem to be reduced by avoiding sugary or high carb foods and drinks on fast days (and possibly just before fasting), most probably because it keeps the body using fat rather than switching back to glucose as a fuel.

Jeany, the milk probably gave you enough of a sugar boost to stave off the migraine (milk contains the sugar, lactose).

Is anyone *measuring* blood sugar, or describing how they feel and attributing it to low blood sugar ?

[carorees]

Not as far as I know, but I based my answer on what I have seen Dr M reply to people on twitter with this question.

These are the symptoms of hypoglycaemia (low blood sugar) according to the American Diabetes Association:

shakiness, dizziness, sweating, hunger, headache, pale skin color, sudden moodiness or behavior changes (such as crying for no apparent reason), clumsy or jerky movements, seizure, difficulty paying attention or confusion, and tingling sensations around the mouth.

And here is a paper (not too recent unfortunately) about headache occurring during fasting. The authors conclude

In most cases, fasting headache has the same clinical features as tension-type headache and the probability of onset increases directly with the duration of fasting.Hypoglycemia and caffeine withdrawal have been especially implicated as causative factors, but much remains to be understood about this topic.

thanks for those replies, really interesting.

what I found is that before I started the diet, I was well known amongst all my friends and family for being bonkers when I didn't get fed. I wasn't overweight, just couldn't survive for long periods without food (over, say, 5 hours)

now, 5 months into the 5:2, I've found that those symptoms have gone - it's almost as if my body has 'reset' itself in response to lack of food.

Does this make sense to anyone out there?

If you have genuine hyperglycaemia and aren't diabetic then it is possible that the fasting has improved your insulin sensitivity or similar and reduced the problem, but for you to have actually low blood sugar (measured) requires either a liver that isn't working properly or some other systems failure so it may be worth getting it checked out.

[carorees]

Fasting hypoglycemia (low blood sugar) is a well known phenomenon. It is not the result of liver problems. It is due to resistance to the effects of growth hormone released during fasting probably because of hyperinsulinemia (too high insulin) resulting from insulin resistance. Overweight is associated with insulin resistance as part of the "metabolic syndrome" so could apply to many people starting 5:2 . Fasting and loss of weight reduce insulin resistance, lower insulin and restore the sensitivity to growth hormone.

Hypoglycaemia in people who are not fasting is, of course a sign that something needs checking.

Hyperglycaemia does not tend to have symptoms until really severe, as in undiagnosed diabetes. The symptoms of headache, dizziness, mood change etc are all typical of hypoglycaemia. There is also reactive hypoglycaemia when people get symptoms after eating sugary foods because it triggers a massive insulin release causing too much sugar to leave the blood.

It almost feels psychological to me - on fasting days when I just can't have food whenever I feel like it, it's almost like I can switch off the old symptoms I used to get when I didn't eat regularly (had previously made sure I ate something every few hours!) - I've now not eaten since about 8pm last night and I'm trying to go through til the same time tonight til I eat my one main meal. It's so strange not feeling shaky or weak or dizzy. In fact if anything I feel mentally sharp and slightly twitchy with energy!?

I've been putting my fast day headaches down to either low blood sugar or not enough salt (I also got a leg cramp last night which makes me think it may be salt). Obviously know how to get salt into fast days, but what about sugar without too many calories? A boiled sweet perhaps?

[carorees]

Hi Emza, welcome to the forum!

As your body gets better at switching into fat burning you shouldn't get the headaches. Having a sweet will stop your body from switching to fat burning, so my advice would be to keep hydrated, have enough salt and take a paracetamol!

your body regulates blood sugar, it's called glucose homeostasis, if you eat something the level returns to normal after a couple of hours. If your systems don't control blood sugar properly then taking sugar can actually make it worse.

That is very interesting. I have suffered for years with this, where if I say ate lunch,two hours later I would very suddenly feel shaky, break out in a cold sweat all over my body, feel confused & dizzy. I would then have to have some glucose tablets or quickly eat two mars bars! It's a horrible feeling which leaves me very tired afterwards. Doctors have been pretty dismissive, took bloods but all came back normal. But that was because I was probably fine at the time of the blood test. I have not had any blood sugar problems on fasting until I ate two quality street & that triggered it. Any advice welcome.

Blood glucose meters are less than £20 if you want to measure yourself, at pharmacies etc and also Lloyds and the like do blood sugar tests for a fee. Test strips (consumables) for the meters can be had off Ebay.

There's a thing called "reactive hypoglycaemia" where eating takes your blood sugar down below the fasting level as an over-reaction to the food. If you measured your fasting blood sugar one morning, then measure it before lunch and at 30 minutes intervals for 3 hours after eating lunch you would get a picture.

5g of glucose will double your blood sugar, so two mars bars is OTT.

Thanks for that Phil. I'll buy a test kit, and look into reactive hypoglycaemia as that sounds spot on. Is it just controlled by diet ?
(Also, Caroline, each time I see a post from you I read your user name as 'calories' instead of 'Carorees'!. I think I must have them on my mind!)