Unfortunately there are so many variables involved. So many things affect our diabetes. Things such as not feeling well, other meds we take, our last meal, the weather, timing and on and on.
The only way to have any sense of predictability is to be predictable. To have such a regimented routine that you can set your watch by your own actions. To have such a stable diet that there is never a question about what your next meal will be.
Me I like a little bit of variety in my life so I'm going to keep chasing that moving target.
Gary S