This book took me 15 years to write.

Not really 15 years of writing … more like a decade and a half of evolution.

The 5-Factor evolution started when I was a “husky” teenager (“husky” is simply a kinder way of saying overweight). I bought every diet book, fitness magazine, and exotic weight loss pill, powder, and bar! I tried weight training, step aerobics classes, Pilates, and yoga. I experimented with diets such as Pritikin, Body For Life, and the Zone. I became interested in exercise and nutrition as a way to make me look and feel better. However, it wasn’t until both of my younger brothers were diagnosed with type 1 diabetes that I became interested in the science of food and how it affects our bodies. I spent eight years in university studying metabolism, biochemistry, nutrition, and physiology. I call this period my “nerd years.”

While I was in graduate school, the 5-Factor evolution continued as I began to work as a nutrition scientist for the Canadian Department of National Defense. I learned a great deal about research. Not only did I perform my own nutrition studies (breaking many test tubes in the process), but I also learned how to assess existing nutrition research. Equipped with studies that could definitively support or refute popular diet info, I began to question many dietary practices. I thought more critically about claims I heard about popular diet programs and weight loss supplements.

I reread all the diet books I had previously treated as gospel and underlined all of the “facts” the books used to support their claims. I then set out to find the research these claims were based on. To my chagrin, I realized most diets and weight loss strategies are quick-fix programs based on half-truths and flat-out fabrications.

I knew there had to be a way of eating healthy that would also be realistic. I wanted a program based on real truth, real science, and real people’s lifestyles, a sensible system that would promote fat loss and enjoyment.

My 5-Factor evolution continued as my nutrition and fitness practice grew. I developed and refined my nutrition plan and applied it to clients with amazing results. My program garnered the attention of actors who wanted to tone up for upcoming roles. Nineteen films, nine television shows, and more than 50 actor and musician clients later, my 5-Factor Diet has helped the likes of Halle Berry, Alicia Keys, Kanye West, Mandy Moore, Eva Mendes, Rachel Weisz, Rick Fox, John Mayer, Brendan Fraser, Stephen Dorff, Robert Downey Jr., and Benjamin Bratt.

In 2005 my first book, 5-Factor Fitness, hit the top of two bestseller lists. Though 5-Factor Fitness was primarily an exercise plan, it contained a brief introduction to the 5-Factor Diet and offered a number of quick 5-Factor recipes. I received more than 5,000 emails from people who had purchased 5-Factor Fitness and had shed anywhere from 5 to 87 pounds! Nearly all of them requested more 5-Factor recipes and wanted to know more about the 5-Factor Diet.

So, with great pride, I present you with the last diet book you will ever purchase. Welcome to The 5-Factor Diet.

Harley Pasternak, M. Sc.