Sometimes I think that any question about health and diet can be answered by in turn asking another question.
Did people do it 11,000 years ago?
Why 11,000? Because it was 10,000 years ago that humans got the idea to stop roaming around so much and to plant crops and raise animals as their primary food-sources. (I'm simplifying here)
From an evolutionary standpoint, 10,000 years is nothing of course, and so we are genetically a world of hunters and gatherers living in a strange and foreign land of pre-packaged food and moving vehicles. This situation is messing with our bodies of course.
So, my theory is that if we stay as close as reasonably possible to the kind of life choices a hunter gatherer would have made 11,000 years ago, our bodies will be happier, they will be in their environment, so to speak. This means walking a lot. Going to sleep early, rising with the sun, and changing our patterns with the seasons. This means eating small meals and eating them often. It means that for any given food a certain amount of energy should have gone into eating it. When we stray away from these basics we get fat, we get heart disease, we get constipation, and we feel lousy.
Now I'm not saying we should live like cavemen or not have a deep appreciation for the ease and safety of modern life. I for one am quite happy to not have to worry about being attacked by lions and having access to doctors even if I was. I'm saying we need to be a little more hunter-gatherer because it's in our own best interest.
We're stuck with millions of years of genetic baggage that does stuff like store fat just in case the next meal doesn't come, that sends stress related chemicals rushing through our body even in non-dangerous situations like having a report due. It would be nice if it were different, and perhaps in a few millennia we will evolve to run efficiently on no exercise and fatty foods, but for now, we're stuck with what we've got. And the choice is to either get with it or get sick.
So I look at the stuff I'm doing in this project. Eating a lot of fruit and lightly cooked vegetables, a good amount of protein, very few refined starches, and exercising a lot. And I'm feeling and looking much better by leaps and bounds.
I like to imagine a stone age hunter-gatherer cocking his eyebrow and saying...