Matt Chan explains how to create a baseline Zone Diet plan for competitive athletes and how to intelligently deviate from it in this video shot at a CrossFit Competitor's Course at CrossFit Park City.

Only 10 percent of CrossFit Games athletes say they weigh and measure their food, Chan notes in Part 1.

"Now you may say, 'Oh, I guess that's not important.' But in my opinion what that says to me is that 90 percent of the Games athletes can improve," says the Level 1 Seminar Staff member who finished second at this year's CrossFit Games.