There was a time where the low alert on my CGM, or the mental indicator in brain, was set at 3.9. That was when I’d reach for some glucose tabs and do something to fix my low.

When my blood sugar was sitting in the low 4s, I’d be tempted to ride it out more often than not to see if I could avoid glucose tabs. Because honestly, does anyone really like eating glucose tabs? That strategy almost never worked, often leading to my hypo brain emptying the kitchen cupboards.

Let me say this. Lows are fatiguing. The longer I’m low, and the lower my low is, the more depleted I feel. It’s a link I’ve drawn this year, as I’ve been continuing to focus on sleeping well and feeling energised enough to get through my day. My lows definitely needed more attention than I was giving them. The attention that I can best describe with one number and one number alone.


That’s the low threshold which I have set for my CGM to alert me that my blood sugar is trending low. I’m ultimately setting myself up for more annoying alerts than what I’d like. But I can live with those extra alerts, because it’s a tactic that’s helped me massively in more promptly addressing my lows and reducing my time below target.

4.4 is like a cushion. A buffer. It buys me time to treat that low while I’m still feeling good, and technically not yet ‘below target.’

For reporting purposes, my low threshold is different to that on my CGM. In Dexcom Clarity, I’ve defined my low threshold as 3.9. That’s what I was educated with, and that’s also the consensus I’ve heard from CDE Jenny Smith on the Juicebox Podcast (which is well worth a listen).

At the end of last year, I’d typically be looking at least 4-5% below target. During rougher diabetes periods, that could even be as high as 8%. It was never something easy for me to bring down. But today, my most recent 30 days look like this.

I’ve rolled my eyes in the past at healthcare professionals and their ‘edginess’ around lows. I’ve had a plastic cup of hypo fluid thrust in front of me as soon I produce a 4.0 on the clinic meter. I still think that lows are not as scary when you actually have to live with them. But I’ve come to agree with my clinic nurses on treating them with urgency.

While I don’t treat my lows with a fear of collapsing at the forefront of my mind, I treat them for me.

Less time below target = greater energy and greater happiness.


  1. The higher the carb diet the more insulin that may be required including corrections doses and the higher risk of fluctuating bsl and hypos. This is from the Typeonegrit site and there is the study of adults. children and teenagers using Dr Bernstein’s methods showing average HBAIC about 5.6%, very low rate of hypos, good inrange (stipulated by Dr B as the non-diabetic range of 3.9 to 6.2 mmol/l), and in children and teenagers, good growth rates – this study would appear to answer all the criticisms that Dietitians Association of Australia (DAA) levels against low carb diets in TID children. And whilst not known to be diabetic how did Inuit and Laplander children survive in the centuries that these peoples had very little if any carbohydrate in their diets? These peoples’ survival also quashes the idea that one needs 150 g carb daily for brain function. We now know (according to many scientists) that approx 80% of the brain runs well on ketones from fat metabolism and that human breast milk, particularly early on, has lots of fat and breast-feeding babies are often in ketosis at the beginning of breast feedings. ( see Dr Noakes Foundation and his report on his trial). Furthermore the idea that saturated fat intake is linked with heart disease has been debunked, in Cochrane reviews on 2000, 2011, 2015 and 2020 – so the need to restrict fats, particularly saturated fats has meant no need to keep diets high in carbs (see you tube Dr Zoe Harcombe – on the Fat epidemic 2019 and others). That DAA has not changed tack on the saturated fat-heart disease hypothesis despite the evidence above (and more) could be alleged as damaging to diabetic’s and others’ health ( see DR Noakes talks on the history of saturated fat and cholesterol.) Hypos are bad news but have we been misguided, intentionally or otherwise, and thus have collectively suffered?

    • I don’t believe that there is any one size fits all when it comes to managing diabetes, and what’s best for you might not be the same for another. Just as you clearly don’t like seeing low carb diets being demonised (and that’s fair enough), I don’t find it helpful to demonise insulin or carbohydrates. If it works for you and you’re happy, then that’s great! Let’s respect our differences.

  2. Interesting insight, thanks Frank. The annoying thing about treating a low is that no matter how fast acting the glucose source, there’s still a bit of a delay in it absorbing — so even if you drink liquid glucose at 3.9, it’s still going to be five or ten minutes until it starts affecting your sugars. And during that time you’re ravenously hungry. So your approach of treating at 4.4 is quite sensible. I wonder if it’s what the pump makers try to do with ‘trending low’ alerts. I have always disabled them because I figure they’d be annoying.

  3. Rachel Coates

    Hi Frank. Seems like a plan as My hypos can give me clear out the kitchen hunger. Would you treat 4.4 if you could see your trend was up? I appreciate we are all different but what would you eat for 4.4?

    • Hi Rachel. If I could see I was trending upwards, no I probably wouldn’t treat. It would also depend on how much active insulin on board there is. For example, if I haven’t eaten or taken insulin in the last 3-4 hours, I might just have a glucose tab. If it was a 4.4 right after a meal and insulin, I would drink some juice. It all depends on the situation.

  4. mjw13

    Hi Frank, lows can be tricky as sometimes I can feel I’m going low, and other times I can be low and be surprised to see I am low. My low is set at 80 (US customary units) that way I can catch the low BEFORE it heads even further downward and drink O.J. or eat a graham cracker.

    And of course as you said it depends on the situation. I have a very sensitive immune system so whenever I put a new CGM in I have to wait 12 hours to get an accurate reading. Yesterday the CGM was put in around 5:00PM and at 9:00P.M. the alarm went off saying I was going under 80. I grabbed a half graham cracker then thought to myself, why didn’t I do a meter stick FIRST before eating the graham? My meter said I was at 140! And now of course going up! I DID NOT need to correct the supposed low!

    As one diabetic put it, “Diabetes is a daily science experiment!”

  5. Hey I ended up in a fountain after falling over from a low. Yeah i get the grind of lows as they fall get worse and more difficult to come back from. Save your pants, stay out of fountains. Treat the lows.

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