This is not a recipe, but my go to snack lately is peanut butter smeared right on a banana with a glass of milk. I think bananas are maybe higher in carbs, so not sure that's great for a low sugar diet...but sure is good for leg cramps, etc. and I suppose the banana is a healthier vehicle for the PB than a piece of bread!
I am also a big fan of "healthy" muffins. I started baking the all the time for DS, since they're a great toddler snack. My "go to" recipe is oatmeal muffins with fruit added (I can post the recipe later as I've modified it to be much healthier than the regular recipe I have from an old mennonite cookbook) and I also like this recipe for whole wheat honey pumpkin muffins: http://allrecipes.com/recipe/pumpkin-wheat-honey-muffins/. For the pumpkin muffin recipe, I skip the brown sugar and sub a bit of agave nectar instead (but probably like 1/8 of a cup and they're plenty sweet). I don't usually have walnuts in the house so just add the raisins, and I like to bake with coconut oil so use that in place of the vegetable oil (if you wanted a lower fat version you could sub apple sauce, but I am a fan of healthy fats). I've made them without eggs many times as DS can't have chicken eggs, by using 1 banana, and 1 portion of commercial egg replacer. They also turn out well with spelt flour, which is what I usually use since DS isn't supposed to eat wheat.
Also, guacamole is great to have for snacks. We always have avocado in the house, it's a total staple. I don't have a "recipe" per se, but use about 1/2 a small to medium tomato, grated into a bowl with 2 ripe avocadoes, the juice from one lime, 3 or so cloves of pressed garlic, and kosher salt and chili powder to taste, all mushed up together nice and smooth (a food processor is best to get it really creamy). Great with tortilla chips or baked whole wheat pita chips for a healthier treat option.
Hard boiled eggs are always good to have on hand as well. They are an easy, make-ahead protien source. Good for topping salad, making sandwiches or just eating on their own.
And, fruit smoothies are a go to in our house as well, for breakfast or as a snack (also very toddler friendly!). My "base" is always a ripe banana or two, one half to one whole ripe avocado, usually a handfull or so of blueberries since I have a pile frozen from last summer, almond milk (plain or vanilla, but you can use cows milk or another type of milk as well), and then whatever other fruit I have on hand that is ripe: mango, really ripe pear (good way to get rid of over-ripe, mushy or bruised pears cause it still tastes good), raspberries, orange, apple sauce, strawberry...adding greek yogurt is a good way to get protien if you do dairy, and protien powder is also an option as well for a protein boost. I need to try spinich at some point...