Many doctors don't worry about blood sugar as long as the A1c test is in normal range. The medical community is glucose centric when considering metabolic health. But high blood sugars can spike after meals which may not show up in the A1c because the glucose levels are low enough in the fasting periods. But the reality is a person can be metabolically unhealthy for ten or even twenty years before it finally shows up in the standard A1c test (even in a non obese and even thin person). High glucose is the symptom. It is high fasting insulin that is the base problem that needs to be addressed in such situations. 

Here is a researcher whose specialty is insulin research. Everyone could benefit from what he has to say, even if they think they are healthy and does not apply to them. For diabetic or pre diabetic people, it is a must listen. I follow him every chance I get. Researcher Dr Benjamin Bikman.

https://www.youtube.com/watch?v=mfR9wIONWAk&t=940s

As long as a person has high insulin levels, burning off body fat (using up stored groceries) is nearly impossible. A person can do it the hard way by starving the body of calories to the point insulin will go low (but energy levels will be terrible and hunger horrible). Or a person can stop eating the foods that spike insulin to lower it. Once insulin is low the body machinery can change it metabolism to fat burning (instead of mostly glucose) and start using up some of the stored energy in body fat the way nature and our evolution and creator designed it.