You know all that stuff you've been told for years not to eat–like animal fat, eggs and butter? Well, Nina Planck, the author of "Real Food: What to Eat and Why," wants you to know that it's actually all okay. In fact, the founder of London Farmers' Markets believes that our society is less healthy because we have eliminated many of these kinds of foods from our diets in favor of industrially processed alternatives.

Planck's concept of "real food" is grounded in her mother's lessons on the farm in rural Virginia where she grew up: food should be whole, nutritional, simple and unprocessed–and it shouldn't require lots of ingredients. Essentially, we should eat the kinds of foods our ancestors did, she says, instead of settling for less-healthy, industrially engineered "ersatz food."

Planck is a big proponent of dairy and, in particular, unpasteurized, unhomogenized milk, which she says is safe as long as you know (and trust the hygiene standards of) the farmer you get it from. In fact, she thinks that raw milk is like a "gateway drug" to better eating, generally. And while industrial meat production is often blamed for environmental damage, Planck says that eating grass-fed meat can actually help the environment.