Low carb but continued high BG (type 1)

Hi all - my first post here so please be gentle!

I've been type 1 for almost 8 years and my control has been pretty poor for a few years now - in fact, it's probably never been good, but I just didn't pay as much attention previously.

Anyway, I've recently got myself a Libre 2 and, in doing so, noticed how insanely high my spikes were when following the traditional carb-heavy diet. For instance, a breakfast of oats, whey protein and a banana would send me up in the 20s (mmol) and would occasionally drop back to a normal range, but usually stay in the 12-15 range regardless of how much insulin I would take.

About 2 weeks ago, I started a low carb diet to try and get some control, with a macro ratio of roughly 50-70g carbs/150g protein/150g fat. This has helped somewhat - for example, my Libre 14 day time in target has increased from 48% to 61%, and >13.3 has decreased from 16% to 3% - however, I'm finding myself stuck around the 9-12mmol range constantly.

I seem to be gradually increasing throughout the day which leads to me injecting more and more Novorapid throughout the day. An occasional pattern seems to be a spike 2 hours after I've eaten, followed by a gradual rise for a few hours later, so I have to take up to three separate injections for a meal, one immediately for any carbs, one 2 hours later, and occasionally an additional a few hours after that (although at that point it's usually time to eat again).

As an example, today I've only eaten about 40g carbs from blueberries, a glass of milk, some spinach and a few squares of dark chocolate, yet I've had to inject 8.5u Novorapid to cover this (and I'm still around 10mmol on average). As a comparison, when I was on a carb heavy diet, my ratio would usually be 1:10 to 1:15, so it seems as if my insulin resistance has somehow increased which surprises me as I'm in pretty good shape - 5'8, 150lbs, about 15% body fat and lift weights 3x a week.

I've only recently dropped my basal (Levemir) dosage after a few basal fasting tests indicated my dose was too high, and my current dosage seems to keep me pretty level, albeit too high.

I know I'm still new to the low carb diet so it could be my body adapting to it, but I'm already a little frustrated as the general consensus seems to suggest BG levels drop more or less straight away, while mine are a still too high.

Does anybody have any suggestions or insights that could help? I'm in the middle of reading Diabetes Solution but I'm not sure how much of the method I'll be able to put into practice without being on regular insulin.

Thanks in advance, looking forward to discussing in more detail.

Thanks for your response @EllieM

If I do have an underlying infection, it's not something presenting any obvious symptoms. I've not had Covid as far as I'm aware, and I've been vaccinated so I'd be unlikely to have it rough.

My night and fasting readings are roughly the same at the moment (but can be too high, 10-12mmol roughly), although this does change quite frequently. A few weeks ago I dropped my nighttime Levemir from 6u to 5u which seemed to be right based on my night vs morning readings, but I've had to drop it again to 4u as 5u started dropping me too much again. It's worth noting that I occasionally have unexplained spikes at around 2-3am. Could be dawn phenomenon or even delayed stomach emptying, I'm not sure.

If I up the bolus for the meal, it'll likely be too much in the short term and I'll go low. I'm usually OK for the first two hours when Novorapid should be peaking, so any more bolus would probably send me low, followed by a 2 hour spike.

As for my team, they're pretty rubbish in all honesty. I don't have a dedicated team per se - there are various diabetic nurses at the hospital, and if I need to speak to anybody I have to leave a voicemail and it's total pot luck who calls me back, and 9 times of out 10 it's somebody I've never spoken to before and they have no knowledge of my medical history. It's rare I get advice that actually helps, they just seem to give me basic cookie cutter advice that doesn't actually address the problem I'm having at the time. In fact, I'm still waiting for them to call me back after the voicemail I left them last Thursday for something unrelated.

Well I'm actually in the middle of the remote DAFNE course with the aim of going onto the pump. I asked about this at my last appointment and they were open to it fortunately, but we'll see how that goes after the course has finished I guess.