After reading Michael Pollan's groundbreaking book "The Omnivore's Dilemma," many people asked the food activist what they should eat. He answered everyone at once with his 2008 book "In Defense of Food: An Eater's Manifesto." The book spent six weeks at the top of the New York Times bestseller list, and his answer can be summed up in seven words: "Eat food. Not too much. Mostly plants."

Now, "In Defense of Food" has been turned into a documentary that "debunks the daily media barrage of conflicting claims about nutrition." In the film, Pollan travels around the world visiting supermarket aisles while continuing to answer the question, "What should I eat to be healthy?"

The timing of this documentary film is beneficial. Many of us have spent the holidays eating a whole lot of food and chances are much of it was not plant-based. It will be a good reminder to readjust our eating habits for the new year.

"In Defense of Food" premieres on PBS Dec. 30. Check your local listing for times.

Robin Shreeves ( @rshreeves ) focuses on food from a family perspective from her home base in New Jersey.