I normally don't post on online forums, but the last month here on MDA has convinced me that this must be the friendliest, most supportive, best spelling bunch on the internet. So I thought I'd pitch in on my experiences with being Primal.
Background: I'm 27, married with one 5 month old son, and work a desk job as a mechanical engineer.
I found my way here from Boing Boing who had a link to Free the Animal's article on not using shampoo. His site referenced MDA. I read a while, bought Mark's book, and decided to experiment with going Primal.
About 2 years ago my wife was diagnosed with hereditary high cholesterol. To keep her off meds, we switched to a whole food diet and got off of red meat. When we made that change I dropped some weight from college. I was never very overweight, probably 5'10" and 180 at the time. Not overweight, but soft.
I've been eating 90% primal for about a month now and have dropped from ~175 lbs to 163 this morning. Most of the weight seems to be from my love handle area which is where I tend to keep my extra weight. The afternoon crash is almost non-existant now. I sleep better and have more energy in the morning. After a few days I lost my cravings for sweets, bread, and pasta (I do make an exception for a piece of my wife's homemade artisan bread).
My next step is to get back in to lifting heavy things to build my muscle back up. I haven't done much strength training since college.
All in all, I've been pretty pleased with my experiment so far.