Be still my beating heart, but I think I've found the meal-replacement bar of my dreams for an active day. At 390 calories, this is not a snack, but the Honey Stinger 20g Protein Bar is delicious and kept me going on it and water for about 8 hours of climbing and hiking yesterday. It's so filling, that I only ate 1/3 at a time a couple of hours apart.
They are normally $2.39 but are on sale now at REI for .99! I stumbled upon them the other day. They are coated in chocolate, so that may melt in hot weather. But they are made with whey protein and honey, so they don't have that awful aftertaste so many high-protein bars have.
They come in several flavors, but my favorite so far is Dark Chocolate Cherry Almond Pro.
If you used to depend on Cliff Bars for a meal, this could be a viable Gluten-Free alternative for you!