Ok. I just read through this and it's silly.
Most people don't need meat. Most people in north american society are also pretty clueless as to how to get protein from other sources because the north american diet is ridiculously simplistic and very limited. A huge portion of meat is coupled with some veggies on the side, and that's about it. The rest is usually made up of bread, rice, pasta, or other grains.
What this means is that it it's pretty much impossible to get a complete protein in the typical north american without eating meat. What comes with this is that meat is eaten at just about every single meal, or at least daily, which is honestly completely ridiculous and unhealthy. It's very, very easy to get your daily protein without meat (all you need is a grain and bean, or just a seed, depending), but most people don't. Most people eat too much meat, and a few don't eat any. I mentioned in my other post that I don't have a problem with people eating meat if they do so responsibly (ie, not going to mcdonald's or buying prepackaged garbage loaded with artificial hormones, etc. etc).
Are people naturally meat eaters? Kind of. I mean throughout most of our existence we've lived as hunter gatherers, and because of our physiology (particularly our brain to which we devote a huge amount of energy) it is, in the wild, difficult to sustain ourselves without the consumption of meat. And incidentally people have seemed to have always eaten meat, however in much, much smaller quantities. People might have meat for one meal out of a week, and the rest is usually composed of plant matter. Dental records and the diets of modern food foragers do confirm this.
Do certain people need meat? I have to say that some people probably do, and it tends to correspond to blood types (specifically people who are O tend to need meat), it's for some difficult to get enough iron and vitamin b12 as well some other nutrients without occasionally eating meat. And again, this I don't really object to. If you do it responsibly and don't overload your system with meat, then that's just fine with me.
I will say that dairy is absolutely not natural for us to eat, because we lose our lactase (the enzyme for digesting lactose) after we've been weened off our mother's milk.