The Zone ratios, 40/30/30, are a critical starting point, Sears has written, to achieving the zone where the hormonal reaction to what you eat is optimized. Too much carbohydrate triggers too much insulin response, Sears says, which over time can lead to insulin resistance, a step toward Type-2 diabetes. An appropriate amount of protein in every meal, Sears says, can release enough of the hormone glucagon to balance out insulin stimulated by carbohydrates. Sears writes that fats are hormonally neutral but send the invaluable message to the brain that you’re full.
I followed the Zone Diet with a scientific zealousness over a six-week period between mid-August to the end of September.
“Following the Zone diet can be hard work - Sears told me over the phone - What I’ve tried to do with my books is give people the tools to make it easier.”
The first few days were challenging. To find the prescription, I subtracted my body fat in pounds from my overall body weight to come up with my lean muscle mass. I also factored in my overall activity level every day, including the intensity, to identify how much protein I needed, in grams, every day. From this total number I extrapolated (using the formula in Sears’ books) the number of carbohydrate grams and fat grams to work in concert with the protein.
At the beginning of the six weeks, I weighed in and had my body fat percentage measured. At the end, my athletic performance improved in both a basic running time trial and a variety of strength moves. I lost four pounds of weight and my body fat percentage dropped three percent, or one full percentage point.
The challenge of pushing myself to follow the Zone doctrine also shifted my diet into an uptake of more raw vegetables than I have ever eaten. Although the 40 percent carb goal is lower than a 60 percent or higher goal as advised in weight loss programs like the Pritikin diet, if you strive to get those calories from vegetables and fruits rather than grains, you end up eating a lot more sheer volume of food than you might imagine. I never went away from a meal hungry during those six weeks and cravings for sweets and desserts were drowned away.
To incorporate the Zone diet into my long-term lifestyle, I’d need to invest more time in learning recipes, for variety’s sake.
Murphy is the Editorial Director of Competitor Magazine. A 2:38 marathoner and five-time Ironman finisher, he is the former editorial director of Triathlete Magazine and Inside Triathlon. His writing has also appeared in Outside Magazine and Runner’s World.