hello!! pre-diabetic, and a couple of questions

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hello!! pre-diabetic, and a couple of questions

This topic contains 6 replies, has 3 voices, and was last updated by  sw600 6 years, 5 months ago.

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  • Hi all

    I started the 5:2 at the beginning of September, so far it’s going OK and I’m surprised at how easy it is to stick to. I have never dieted before; I don’t *think* I need to lose weight (male 177cm/70kg), although I don’t have a 6-pack so I guess there is still spare fat there!

    I’m doing it in response to high blood sugar (and moderately high cholesterol) readings at my 40-year-old checkup in April, as I understand that it may help with insulin resistance. HBA1c was 44 (pre-diabetic), and a re-test with a private GP later that week said 42, so still pre-diabetic I think; although the margin of error is quite large, it’s still high. I had it re-tested at the start of Sept and it was 40, so perhaps my efforts to that date (less bingeing on big bags of sweets and chocolate, drinking fewer days per week) were helping.

    I’ll re-test 12 weeks after starting this (so end of Nov) as that is a typical red blood cell lifespan, which is what the HBA1c test is based around, so that will be interesting. It’s so difficult to draw any conclusions from this though, as for example I was doing weekly big (200km) bike rides to prepare for an event in July, and eating as much glucose and simple carbs as I could during those, which must have affected my readings. I’m not doing those rides now.

    Anyway, with the scene set I have two questions that I hope someone may be able to answer.

    Firstly, I am cycling to work every weekday which is 17km/45 min each way, and I have a power meter on my bike which accurately determines calories burned, some 350 each way so 700 in total. Which group does this put me in on the TDEE counter? I don’t do a huge amount of exercise other than that, perhaps 15 mins walking per day.

    Secondly if I continue with this regime, where I am losing weight, there will come a point when I don’t want to lose anymore, perhaps if that 6-pack appears 🙂 Do the benefits still accrue if you simply eat more on the other days to compensate, so that weekly total calories are 7x TDEE?

    Hi sw and welcome:

    As for your exercise level, the numbers you give put you between light and moderately active. The standard advice is to choose the lower of the two for your starting TDEE estimate.

    As for your ‘power meter’, well, unless it has an input for your genetic make-up, it will only be accurate by accident. Research shows that different people doing the exact same kind and amount of exercise burn different numbers of calories. So if you have two people with the same physical make-up (weight, bmi, etc.) riding a stationary bike at the exact same speed for the exact same amount of time, one might burn 200 cal. while the other only 150 cal. They have confirmed this using sets of twins (one set 200, second set 150) so the conclusion is cal. burn for exercise has a genetic component. And if your power meter does not have inputs for your weight, height (wind resistance), etc. it is just guessing anyway. Here is some information on TDEE: https://thefastdiet.co.uk/forums/topic/tdee-for-the-curious-or-why-dont-i-lose-weight-faster/

    The only ‘benefits’ resulting from 5:2 that have been clinically proven are those that come from weight loss – lower blood pressure, better cholesterol levels, etc. The ‘other benefits’ that are mentioned in the book have not been proven to come from following 5:2. This is understandable once you realize that on 5:2 you can eat any kind of diet – high fat, low fat, high processed carb, no processed carb, etc. – and you would have to do a clinical study for each diet to confirm 5:2 is the cause of the benefit, if any. That will require literally hundreds of studies over a generation or two. There has not been time to do these studies, so claiming 5:2 causes other benefits is a bit premature.

    Significant benefits have been proven to come from longer term water fasting (3/4 or more days) done several times a year. Here are some tips: https://thefastdiet.co.uk/forums/topic/the-basics-for-newbies-your-questions-answered/

    Good Luck!

    The power meter is essentially a strain gauge and a cadence sensor in the crank arm, the combination of readings from which allows power to be trivially determined (to 5% accuracy or so). Of course determining how many calories were expended in creating this power is an estimate, but an estimate which certainly has fewer degrees of freedom than one from a fitbit or whatever. Left to its own devices my garmin will typically display almost double this value when working from heart-rate/GPS data alone, which is something that people should be aware of when relying on such data.

    I’ll keep on with the 5:2 and see what the numbers are at the end of the initial 12 weeks, if they are better then the combination of unproven actual effects, psychosomatic effects and whatever else will have been worth it. Any with my cholesterol a little high (ratio of overall to HDL is 6.0) then any benefits in that area are also welcomed, I’ll test that again too.

    I sincerely hope that I don’t have to endure any 3 or 4 day water fasting episodes, fingers crossed I can keep things in check without that torture!

    Hi sw:

    Water fasting seems like torture to those that don’t do it, but it really is quite liberating and enjoyable, not to mention healthy.

    By the way, the longest documented, medically supervised water fast lasted for 54 weeks and 3 days, and the guy was just fine, lest you think you have to eat food all of the time or die. And he didn’t even go into ‘starvation mode’!

    @sw. Your 70kg and 177cm tall so I wouldn’t describe you as overweight. In fact youre pretty well spot on Id say. HbA1C is typically reported as a percentage. A value of less than 5.6% is usually OK. So your reading of 40, are you meaning 4.0%?

    Are you carb loading or eating a lot of sugary foods? Probably not necessary if youre only doing 45 minute rides. Perhaps a change in diet may be a better option? Less simple carbs/sugar. There is nothing wrong with fasting if that’s the way you want to go about it. I fast one day per week and slightly overcompensate the rest of the week so that I maintain the same weight.

    hba1c is presented in different units depending on stuff like which country you’re in. 42 mmol/mol is approx 6%, 40mmol/mol is approx 5.8%. So mine are high.

    Carbs are only for the longer rides (3-9 hours), I use simple sugars, energy bars etc since it’s difficult to shove enough steamed fish and brown rice into the jersey pockets to cover all the calories burned 🙂

    I’m not expecting this to be a silver bullet to fix blood sugars and cholesterol. I’ve never felt like I’ve needed to control eating or restrict anything in my life really, so a defined thing to do a couple of days a week (or as you say, to progress to just one day in ‘maintenance mode’) could be a good thing to focus on, and it has helped me to think about exactly what I should be eating on the other days too.

    Update for anyone interested. So in 12 weeks of 5:2, (which to be fair has also been accompanied by me just thinking more about what I’m eating, so difficult to tease out exactly what is achieved by 5:2 alone):

    Weight down from 71 kg to 65.5 kg.
    LDL (bad) cholesterol down from 5.1 to 4.
    HDL (good) cholesterol no change at 1.3
    Triglycerides down from 1.3 to 0.5
    So ratio of total:HCL down from 5.1 to 4.1, which is great.

    fasting glucose was unchanged at 4.8 (so OK)
    HBA1C was unchanged at 40 (or 5.8%) (so right at the upper end of acceptable).

    The long and short of that is that I am a lot faster up hills on the bike due to losing ~10% of body weight! Cholesterol results good, blood sugars no change. Perhaps any insulin resistance benefits due to fasting may take longer to accrue, or perhaps it’s a load of rubbish.

    Still, I’ll keep doing the 5:2 as my wife has started now and I’m keeping her company 🙂 I could probably lose another 3 kg and still be OK, after that I don’t want to be any thinner.

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