Yes, I sometimes to get really bad anxiety, and around times where it used to happen really bad I couldn't eat, and when that happens I would lose a lot of weight and have short/infrequent periods. As wonderful as that sounds, it's your body telling you that it's lacking the necessary nutrients and stuff that makes blood. And you kind of need blood. Eating foods with higer iron and protien is important, so if your regular eating doesn't provide that you should take supplements and/or incorporate higher iron/protien foods.

I'm the same exact way! It is very odd because I'll crave just one thing before my period, and while on my period I don't even bother a snack, must less a meal....When I have the craving at the beginning of my period, it's heavier! But since I don't eat much the rest of the 6 days, it's so much lighter. Makes no sense to me. 

Yes when I eat meat mine is a lot heavier, when I stick to my veggies it's really light.. Depends on your diet. Processed foods, like boxed, premade and fast foods are not healthy and have crap in them so your body reacts to those things.. Me personally as a vegetarian I don't have an issue.. Same with my family and friends that are veggies they experience lighter periods too

That can't be healthy