I had been gluten free prior to my first Whole 30 back in October, but it was my first dairy free trial. I'm on a second Whole 30 right now, and in the interim I've eaten very little dairy. My cycle is more regular, and even better...more normal instead of too heavy as it been previously. Something about avoiding dairy seems to balance my hormones.
Sugar is the druggiest drug I've ever had. Immediately after I consume it, I am a "happy drunk": relaxed, chatty, less-inhibited, and so on. I feel AMAZING on sugar. The next day, if I don't dose myself again, I am Mr. Hyde. We're talking rage. I find myself yelling for no reason, hating everyone and everything... It's a bad scene. And, of course, eating sugar makes me want to eat more sugar.
Dairy (primarily casein--I react a lot harder to aged cheese, yogurt, ice cream, etc. than I do fresh cheese or milk) destroys me. Congestion and coughing within minutes, headaches and joint pains within an hour, and then feeling spacey and hungover for a day or two afterward. Goat's milk cheddar did the same thing, but fresh mozzarella doesn't bother me as much. I can tell if a recipe has dairy in it based on how it makes me feel. It is horrible.
Wheat flares eczema I didn't realize I had. I can have one serving a week or so without much consequence, but any more frequently than that and my skin gets itchy and my cuticles start cracking and my scalp starts getting scabby again.
Rice destroys my digestion. It feels like a rock in my stomach and then it totally trashes my gut for a few days.
Soy makes me feel like I have the worst hangover in the world.
I never bothered to reintroduce legumes besides soy (which was less intentional--we got Chinese food one night).
Seriously--things I never thought would happen with regard to food. It's insane.