I have noticed an incredible difference in my moods and energy level since I began eating meat again. I hate that it is true, because I would like to still be vegetarian, on a philosophical level. However, I can't argue with my body. I do have more energy (and I'm sure it's my diet, because nothing else in my life has changed!), I don't tire as easily, and I've lost almost 10 lbs. since changing my diet.
My moods are more stable, too. Dh asked me recently how I've been feeling emotionally, and I replied that I'd been feeling rather short-tempered with the children. His response was surprise, because he thought I'd actually been more patient! He was not picking up on my emotional swings as much, where before, he would politely point out how impatient I was being with the Dc. So, I think that perhaps it's been easier for me to regulate my moods.
I also haven't been feeling like I'm in the depths of despair recently, either. I had been feeling like I was stuck at the bottom of a long, muddy hill with a burden the size of Mt. Everest on my back. I haven't felt that way for several weeks. I am so thankful to feel more like my old self, that it is worth it to be eating meat again.
I think, too, that if I had listened to my body during my last pregnancy, I would have had it much easier in every way, physically, emotionally, labor/birth, etc. I'm just glad that I've started to listen to it again!