How low carb? I dealt with GD in a previous pregnancy and had to have a lot of snacks in the 15 g carb range, always paired with a protein. I ate an absurd amount of string cheese, but usually paired with something like a fiber one bar or half of a piece of fruit. Other common snacks were cottage cheese (with sliced apple and cinnamon mixed in) or whole wheat crackers with cheese and vegetarian pepperoni. I also ate a lot of siggi greek yogurt - very high protein with no fat and low sugar. Hard boiled eggs work as well of course, though they are not low on the fat.