Award-winning science writer Gary Taubes disagrees with the medical community’s most basic rules of dieting. Here, Gary challenges Dr. Oz to reexamine his fundamental assumptions about nutrition and why we gain and lose weight.

Click here to see Dr. Oz and Gary Taubes debate the effectiveness of exercise for weight loss.

Click here to read an excerpt from Gary’s book, Why We Get Fat.

Click here to watch Part 1.

Click here to watch Part 2.