My experience: I'm hypoglycemic -- or was. I was primal for over a year and experienced your exact issue -- it really frustrated me, as I like to IF overnight until lunch. I've found that once I got all the sugar out of my diet -- including fruit -- and increased the fat (I already had a lot of protein), I can go for hours somewhat reliably. Every now and again, I'm really hungry. So be it. I eat. I eat two to three meals on weekends, two meals on weekdays. But I do think the sugar affected my insulin, and the increase in fat satiated me so much more. I now "get" the IF concept and how folks can go for hours without hunger.
Hope that helps in some way.