I saw Michaels original Intermittent fasting programme the day after I had seen my GP for a general check up. I had hit 14stn and was not very happy about that but my blood sugar was in the normal range. I was particularly interested in the stated beneficial effects of reducing the growth hormone. So I started the 5:2 and though already quite fit, upped my exercise. I was amazed to find out how easily I managed, even swimming on fast days. Over the next 3 months I dropped to 12 &1/2 stn. At this point friends started saying I looked a little gaunt, so I adapted my diet. Whilst carrying on with 5:2 I started eating more on my feed days (and more treat foods than i had been eating before the fasting) I carried this on for nearly 3 years. When I went back to my GP for another routine check up, although pretty much at my ideal weight, my blood sugar levels had entered the pre-diabetic range. I was less than happy to hear this given the hoped for beneficial changes I had made. So I have stopped the 5:2 and started eating a low GI diet. My blood sugar levels have stayed in the pre-diabetic range. I’m a little at a loss as to how to progress. Any suggestions welcome.

I can’t imagine 5:2 causing pre-diabetes, the only clue from what you’ve mentioned there is that you started eating more ‘treat’ food during your feed days. using BSD in any form doesn’t recommend this so it sounds like your version has controlled your weight but not your blood sugars.

I’d suggest having a re-read of the actual guidance as maybe it’s changed from when you began 3 years ago? I wasn’t around then. Remember it isn’t so much about how many calories you are having – if anything it’s more about what type. good fats and protein, reducing or removing anything processed or sugary as well as simple carbs. Without knowing exactly what you were eating I can’t suggest anything else but I suspect your treat foods may be the problem rather than the 5:2 approach.

You may be interested to know about a new study published last month which appears to demonstrate the suggestion that fasting can cause diabetes. It turns previous studies upside down, appearing to go against the benefits they claimed. So, the jury is out on this one. I am also unhappy as I have been on the 5:2 for over 4 years, am slim and fit, exercising regularly, with no extra fat and have just discovered, from a blood test taken for something else, that my blood sugar has entered the prediabetic category. I have yet to discuss this development with my doctor.
https://www.sciencedaily.com/releases/2018/05/180520090903.htm

Can I just say that food on its own is not the cause of diabetes. Maybe the wrong foods or too much food causing weight gain and obesity may put a strain on the bodies insulin production. But not eating good food or even the occasional treat. Diabetes T2 can be caused by familial reasons. For example, my mother had T2 so that makes me 40% more likely to have it even without other factors, i.e. I wasn’t overweight of obese, I exercised at the gym most days and swam twice a week but my genes let me down. Maybe lostsock and cazcazt you were always going to be prone to diabetes and maybe you have been avoiding it by being on good diets but sorry, it has now caught up with you. Cazcazt, I think we have be in contact before and you have not had the full story from your doctor yet so it may be the precursor to diabetes or something else. It is good that you follow the research but not all studies are equal. Lostsock, it may be time for you to have a few weeks on the full BSD to try to get out of the pre-diabetic state. The old 5:2 was eat normal on 5 days and fast on 2 and a lot of people just eat the same stuff as they always had. You should be on a strict Mediterranean style diet but with little rice, pasta or bread and around 1200 calories with the fasting days on 800 (was 600 but it has been revised). Give it a go before you have your next test.

I see the test were carried out on rats. Just because a rat’s metabolism reacts in a certain way doesn’t mean ours will too. Some animals need to have fat storages in order for them to function, feed their young, hibernate and so on, so starving them might have a whole unknown effect not related to humans.

I have just read the whole article and the conclusion is that overweight or obese people who try to lose weight using intermittent fasting may very well have underlying metabolic problems in the first place. So she is saying you might already have diabetes but didn’t know it. Pretty much what I have said to cazcazt and lostsock.