What diet changes and exercise helped a prediabetic prevent diabetes?

[LarryEM]

I'm a 45-year-old man with a strong family history of type 2 diabetes; both my parents developed it in their late fifties. My recent annual physical showed my fasting blood glucose is now in the prediabetes range, which was a major wake-up call. My doctor advised weight loss and more exercise, but I need a concrete plan. For those who have successfully focused on diabetes prevention, what specific dietary changes made the biggest impact for you? Did you find cutting out all added sugars more effective than just reducing overall carbohydrates, and what kind of exercise routine—like strength training versus cardio—was most sustainable and beneficial for improving insulin sensitivity?