Good low calorie butter substitute?

ncfitbit

I use this. 50 calories per tablespoon and it's satisfying enough that I often use half a tablespoon. I like it better than any of the other spreads for eating on toast or crumpets, etc., but it does have water or air or whatever added so it just seems to melt rather quickly, but I don't have a problem with that. That's one of the things I dislike about real butter.