Gestational diabetes if you kept same diet

What would your numbers look like if you ate normal and didn’t do the diet - curious bc my dietician said I don’t have this after looking at my numbers (I went on a keto diet the week before test with no carbs at all and they said my muscles couldn’t handle the gluclose and my numbers were 200-300 on test but fasting was 61 ) but in real life charting they are always under 100 and fasting is 60-85 - she said if my numbers were really 300 it would show on my charting and I would need medicine that I would not be able to control it with diet let alone without diet and the way I ate before caused a false positive and it’s in literature to specifically not do that. my doctor questions my diagnosis and has me doing a 2 week chart of eating regular. He said If you had gd and didn’t do the diet ate whatever you want that you would consistently have higher blood sugars that wouldn’t come down at 2 hours. He told me not worry about spiking at 1 hour bc normal people do and as long as I have numbers below 140 at 2 hour mark always eating normal (pizza, burgers, sugars etc) than it’s unlikely I have it. The paper says under 120 but my ob said if you don’t have it and eat whatever you want as long as your number is under 140 at 2 hours you are fine. He said it’s not the spikes but staying at a spike and having trouble coming down which most gd patients have without diet. He said if you eat normally and 50 percent of the time you are over 140 at 2 hours then you have it but if not then I don’t have it.