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@eggyg, I bolus an hour before breakfast, and that’s mainly because of the dawn phenomenon. I use my usual 1:10 ratio though, and add on two extra units, rather than changing the ratio. So if I have a zero carb brekky, I still give myself two units. It’s normally an hour before I have porridge or muesli, if I've got a Libre sensor on, I watch it, and eat when I see the trace start to turn downwards.
Lunchtime, in theory I bolus half an hour before, because I have a fairly carby lunch, with a couple of pieces of fruit. but in practice, if we’ve been out, or I’ve got involved in something, I forget, so then I have to put up with the resulting spike.
Evenings, I bolus at the time of eating, because I have fewer carbs in the evening (no particular reason, but I find a cooked meal works better with a larger ratio of protein and fat to the carb element,).
When I’m out, I never bolus til the food is in front of me, just in case there’s a long wait, or the fire alarm goes off or something. This does cause a spike, but I don’t go out often, and it’s just something I live with.
I have been caught out when I've pre bolused and the insulin seems to have got going a bit too quickly, and i think there’s nothing worse than having to stuff something glucosey just before you’re going to eat something savoury that you’ve been cooking and looking forward to.
I’ve worked all this out for myself, I've never been sent on a course, (though. have done the Bertie online course) I was taught the basics at the hospital clinic, and my surgery nurse knows little about carb counting.(and what she knows is mainly what I've taught her!)