 [ Symptoms ] how long after changing my diet should i expect to see a drop of my blood sugar scores  just curious have recently been diagnosed with type 2 and have changed my diet significantly how long before a diet change would influence my numbers [ Disease ] changes to your diet can have an immediate affect on your daily blood sugars but as for as your hemoglobin a1c levels that takes about 3 months to see a difference that is because the test measures blood sugar management over a 3 month period of time if you keep your blood sugars down consistently your next test should decrease quite a bit for more read glycohemoglobin a1c