I think very vanilla soy milk works the best....but an entire cup of the milk is about 130 calories. I suppose it depends on how much you are putting in.

I've switched to vanilla almond milk. It's 90's calories for a cup of the milk and I just count that figuring if I have 2 cups of coffee they both have around a half cup of milk in them. I like a lot of milk in my coffee, but I also don't usually finish a cup before throwing it out and getting a new hot one so perhaps I am not drinking as much coffee as some.