msucleman, that's because everything is high GI. Even brown rice and whole wheat bread tends to be moderate GI, now low GI.
Now, back to the other question. Calorie dense low GI carbs? Cherries, applies, grapefruit (might want to limit those, since fructose should not be your first choice of carbs). Yogurt, beans, and milk are all calorie-dense low GI carbs as well. You can also change the gi of foods. Take brown rice, and add alot of olive oil and a few beans and some meat to it, and bam, you now have a low gi carb.
I'm a huge believer in low-carb diets, but there is the information you are seeking.