I went low carb following the archevore.com site, which is fairly similar to the primal and paleo stuff. I didn't see any weight loss at all for 6 weeks. It took that long for me to adjust, get over the low carb flu, get my strength back, start to get over the dehydration and electrolyte issues. Then weight loss started for me. And here I am on week 8 now and I'm finally starting to feel that sense of having a lot of energy. But the weight loss is still very slow. It is harder for us women, especially those of us 40 and up. There's a great thread started by paleobird somewhere around here where she sums up what actually works for us women. Sadly, it involves calorie counting. However, eating real food, food with real fat and real protein is satisfying even if you have to restrain yourself a bit.
Female, 5'3", 49, Starting weight: 163lbs. Current weight: 135 (more or less).
I can squat 180lbs, press 72.5lbs and deadlift 185lbs