Anyone on this Forum that has hiked Whitney as a day hike and is prediabetic or diabetic (II)? Curious what you did for dinner the night before and breakfast and food for the day hike? Thanks and hope to hear from you!

I can't answer about specific diets for individuals. However, back in 1991 one of my hiking partners was able to go from the parking lot to the summit in 3 hours 42 minutes. Afterwards, I asked him for some words of advice for future Whitney hikers.

He said, "The night before, eat lots of noodles."

Recovering PD/borderline T2D here--and 3-time Whitney dayhiker. I never worry about eating carbs before or during a strenuous hike like Whitney--in fact, my hiking "food" has devolved to sour gummy bears and butterfinger bites because I just don't crave nuts/cheese/jerky/bars on the trails.

If your D has progressed to the point where you need meds/insulin, I expect it would be best to consult your doctor beforehand, and to test out your regimen on tough training hikes where you are closer to medical services if need arises.