@Beenalongwinter
It's expensive - you pay £300 for the initial kit for all the blood and poo tests and subsequent reports.
The blood glucose monitor comes with some special Zoe muffins. They ask you to eat muffins and their app on your phone links to the blood glucose monitor on your arm to monitor your individual response. People's bodies vary massively in their abilities to process sugar/ carbs.
I haven't done it myself - as I say, the Ozempic is now artificially managing my blood sugar level dips and spikes so there's no point. This is all info I've gleaned from doing a bit of internet research.
I'm interested in eating this way for general health, to feel good and so that when I come off Ozempic I've got a good, sustainable diet in place so (please God) I don't put the weight back on.
The other source of very interesting information about blood sugar level spikes and crashes is 'The Glucose Goddess' - research scientists with a special interest in this. Great YouTube channel.