What does this A1C level of 6.5 indicate?
what do you mean by "glomerular 20"? Did you mean that your glomerular filtration rate (GFR) is 20 mL/h?
Being overweight or obese definitely makes diabetes worse. Loosing weight may make your diabetes disappear. A glucosylated hemoglobin so close to the normal range may drop back to normal. Using metformin is not advised if your GFR is as low as 20mL/h! If this is the case, then only insulin can be used and you should visit a nephrologist.
If the "glomerular 20" is not your GFR then metformin can be continued. Twice daily is usually a well tolerated dosage that provides a great deal of help to blood sugar control.
So your idea sounds very logical to me. It is a medical fact that loosing weight helps a lot and you should try to do it!