Well, I'm temporarily (a year? maybe?) on the GAPS diet, which is
similar to Paleo -- only it does allow three legumes (lentils,
white navy beans, and limas -- the high starch content of other
legumes makes them illegal, not the fact that they are seeds). I've
found that if legumes are prepared well, by soaking for 12-24 hours
to reduce phytates, they are much more easily digestible by most
people. Every culture that consumed legumes used fermenting or
soaking to achieve this. My main question re: paleo is that, as a
lifestyle, it would be SO hard to maintain for a lifetime. It's a
huge challenge for me being on GAPS right now, and there is an end
in sight! (incidentally, I have this opinion about other lifestyle
diets as well, such as raw vegan -- any complete shift in diet for
the rest of your life would be very difficult to sustain, and
somewhat isolating -- though I have no judgement toward those who
make the leap and see positive results.)