After almost 35 years as a type 1 finally seeing a doctor at the hospital, who actually takes time to go through my whole health situation. My reading for the 6 months was 72, which he said was OK but could be better but it has come down.
What frustrates the life out of me however is I typically eat the same things at the same time and have the same work routine. Some days my BG is high others it goes low
Injection sites and timings may be an issue:
1) do you rotate sites?
2) have you noticed a difference between sites (eg. lower bg using the stomach than compared with the thigh)?
Timings:
1) meals high in saturated fat will slow the absorption of carbs giving the insulin more chance of correlating it's peak performance with the breakdown of the carbs in the blood stream;
2) wheat based foods, like bread and pasta (even the wholewheat versions) frequently cause high post-meal rises (even 3-4 hours) and you may find that injecting (say 20-30 minutes) earlier than you normally do will result in better insulin-carb correlation.
The specifics of your particular requirements will need lots of structured testing to build up the data so that you can fine tune your needs.
Another thing to remember is that...
a) meters are permitted an accuracy allowance of 20%;
b) food manufacturers are permitted similar tolerances when listing values;
c) portion sizes are never exactly the same;
d) other factors, like illness, stress, activity (or inactivity), other meds, cleanliness of fingertips, temperature at time of testing, etc. etc. etc. can all affect your blood sugar levels or the way your meter reads it - even if such factors are minimal.
The joys of T1!