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@Madhuskies
Whilst food is the main thing that can affect our BG, there are many other things. Unless we eat exactly the same food, get no illness, do exactly the same amount of exercise at the same time of day, have no stress in our lives, that's the life we live in a bubble where the weather never changes, where we go to sleep at exactly the same time and wake at exactly the same time, we are unlikely to have the same reaction to the same food every time. And even then, if we eat it at a different time of day, the reaction may differ.
Yes, our BG is affected by illness, stress, weather, number of hours sleep we have, how much exercise we do, ...
But, on top of that we have Dawn Phenomenon and Foot on the Floor. This is when our really helpful livers help us start the day by dumping glucose into our blood. This happens to most of use regardless whether we have diabetes or not but it is only those of us "lucky" enough to have diabetes who notice the rise. Some of us can spot a rise starting in the early hours of the morning to give us the energy to get out of bed and start the day - this is Dawn Phenomenon. Others can spot the rise after we get up. It's as if putting the first foot on the floor as we get out of bed sends a signal to our liver to start the lever dump.
I am no medical expert but my guess would be that you are experiencing Foot on The Floor rise. Annoyingly, this is the last BG reading that is likely to come down.
But remember you will never get rid of all spikes - these are perfectly normal. If someone without diabetes tested their BG, it would be different at different times of the day, depending what they eat, exercise, etc.