@Flashtash2014
I would say at the moment, under no circumstances switch to a LCHF diet for a month.
There would be absolutely no benefit to you, if you are considering a LF, primarily carbs very low calories diet straight after. Indeed the change to metabolism from your diet now, then low carb, then back onto carbs again will affect your BG readings, and your bodies and meds reactions. I would also resist the temptation to alter the diet, I used a shake similar to the original (tescos) but if your doctor will prescribe, that's even better. My BG readings were fine, even with the 'high carbs' in the shake. (About 26g a shake in mine)
But to answer the original question, switching from your current diet, with controlled BG readings, to the Newcastle diet and your meds.
It is recommended you stop taking insulin stimulating drugs, such as a glicazide.
The reasoning behind it, is that if you change your diet in the extreme manner of the Newcastle diet, (particuarly as you have BG in the normal range), you may end up going hypo. (The same advice would apply switching to a LC diet, hence another reason why it is an unsuitable diet at the moment as well, without medical support/intervention).
To enable this though, you do need the support of your health care team, you need to monitor your own BG, and have the means to do it provided, and you need regular agreement on changing/decreasing, or even re-introducing meds.
Having said that, even on no meds, it's likely you'll have BG in the normal range within the first week.
But this does need to be tested.
I wasn't on an insulin stimulating drug, I was on Januvia though, which I dropped on day 1, and I was confident of my ability to self monitor,
My nurse was fairly relaxed about it, and I was scheduled for a full blood test after the second week, which was fine.
In fact everything was well in the normal range, apart from my ALT, which was a couple of points over)
However, the odd reading can change, as your body, and liver particularly, are burning fat, and muscle, to keep you going.
I had been on a low fat, low GI portion controlled diet before though, and was starting the Newcastle diet from a 'normal' BMI, but I still lost a stone and a quarter in 5 weeks, so I would say it's well worth the effort. I have just stopped the diet this last weekend, and am building the calories back up.
I will be back on my normal, portion controlled, low GI/GL low fat diet, and am thinking I'll stay on 500mg metformin long term.
The only bad reaction I had was being physically tired, and felt low on energy, so it's not a good diet to do if you are going to be physically active.
I planned the timing around this thought, so could cope, an didn't had to do excessive work for the period.
I have a busy weekend, and more work up to the christmas period, hence the early finish, and the build back up.