I ask this because my boyfriend is largely derisive of paleo circles, insisting that the majority of the world does just fine eating carbs and grains. He acknowledges that sugar isn't great and that people eat too much of it, but for the sake of taste and enjoyment, believes that it has little negative effect on his health- no mood swings, insomnia, etc. He appears to be very healthy with his diet as it is (meaty but for reasons of economy relatively high in pasta, noodles, bread), and has no digestive complaints, sleeps well, and has perfect skin. I, on the other hand, came to paleo after undernourishing myself on a low-fat pescetarian diet, with shades of anorexia, that caused me to switch from low-fat pescetarian to high-fat, low-carb paleo. He often points out that he has always been healthy on his diet, while I still have some problems (due to stress and structural spinal issues), so am hardly the most convincing argument for paleo or any other eating program.
He points out that mankind has done pretty well on grains for thousands of years, and it's only in the last 100 years or so that 'the diseases of civilisation' have really increased. We also live in Japan, where despite eating around a thousand calories of rice every day, people are in pretty good health. He is skeptical of paleo because most people seem to come to it because of some health problem they were suffering, whether it be obesity, GERD, arthritis, IBS and so on. He argues that most sports professionals eat mountains of pasta, bread and so on, and seem to be in perfect health (I agree that many of them look good and turn out superb performances despite living off glucose and grains). He simply doesn't find the argument for paleo convincing because of this, and because he thinks there has been some adaptation over the last few thousand years to allow people to thrive on grains (our Asian environment would support this).
So- has everyone here come to paleo because of some health problem, or were some of you turned onto it merely out of curiosity? It seems somewhat implausible to me that you would give up pizza and so on if you felt like you were in perfect health.