Yes one of the challenges of diabetes management is that it’s a big complicated machine with all sorts of whirring cogs, dials, levers and switches… but we only have access to a handful of controls on the front (carbs, insulin, activity) and the dials we can see are a bit fogged up!
There’s a post here which suggests 42 factors that can affect BG levels
A useful list for when you're making that 'piece of cake' calculation :) ETA: Article about the table: https://diatribe.org/42factors
forum.diabetes.org.uk
One of the frequent ones to confuse people is the ‘dawn phenomenon’ or ‘feet on the floor’, where the liver fires up the burners for the day by releasing stored glucose either in the early hours of the morning, or as soon ay you get out of bed.
This can mean that your levels rise overnight, even though you’ve not eaten anything!