Weston Price, a dentist early in the 20th century, visited indigenous populations across the world to see how their diet affected their health. The healthiest people ate pretty much the opposite of what we are told to eat today, and they suffered from almost no health problems and had few or no dental issues.
Based on his extensive research, including studying other cultures and performing studies on people in our country, new guidelines have been issued. You can find them on the Weston Price Foundation website, and in the book, Nourishing Traditions. I highly recommend looking at both.
According to Weston Price, pregnant and nursing mothers should have a diet that consists primarily of animal products, such as butter, milk and beef, along with eggs, seafood and soaked whole grains. Lacto-fermented foods, which include sauerkraut, are a major part of this diet too. According to Weston Price, saturated fats are actually good for you.
I believe this diet is more in line with the proper way of eating, because it focuses on whole foods from nature, which most of us used to the Western diet are not getting enough of. So take a look at the website, read some of the research, and decide for yourself if our modern diet is really the way to go.