The Zone Chronicles: An In-Depth Look Into The 40-30-30 Diet

  • By TJ Murphy
  • Published Nov 2, 2011
  • Updated Jun 19, 2012 at 12:17 PM UTC

In the November issue of Inside Triathlon, T.J. Murphy writes about Dr. Barry Sears, creator of the Zone Diet, a dietary protocol prescribing 40% carbohydrates, 30% fat and 30% protein that was first practiced by high-performance triathletes like Mike Pigg and Mark Allen. Over the next month in a series of stories for, Murphy will continue his reporting from the past six months of studying and practicing what is commonly referred to as the Zone Diet.

As I describe in the November issue of Inside Triathlon, I recently conducted a phone interview with one of the greatest triathletes of all time, Mike Pigg, to discuss how his diet evolved in the late 1980s from one that was loosely patrolled and high in processed carbohydrates to a more moderate diet that included more attention to quality of the foods and inclusion of protein and healthy fats.

The issue hits newsstands Oct. 25.

When talking with Pigg I realized that I had followed (albeit much later in life and within a far more average athletic career) a similar path. I began to notice that the food I was eating was making a mess out of me. My energy suffered, I wasn’t sleeping well and I wasn’t able to train or enjoy training the way I used to.

The Zone Diet wasn’t my first experiment. But after reading the books and seeing that it wasn’t the radical diet I had previously imagined it to be—the Zone has long been labeled by some as a high-protein, high-fat diet, but when you actually do it you see that it’s not—I was impressed by how much sense it made. When I put it into action starting in late May, I immediately began to feel better. In one six-week period starting in August and ending around October 1, I used before and after measurements of the Zone protocol and lost 2.9% body fat.

Prior to the six week “Nutrition Challenge” that I participated in, I paid a visit to Dr. Sears in his offices in Marblehead, Mass. I accumulated a large quantity of material from research, interviews and my own experience and while the heart of it exists in the story in Inside Triathlon, I will spend the next month doing my best to publish the remainder of it here on

Do I think the Zone Diet is a good one for triathletes? I do. And I wouldn’t be writing about it if I didn’t. Furthermore, I’m convinced that triathletes who haven’t been paying serious attention to the quality and quantity of foods they eat will enjoy increased performance and overall health benefits by giving the Zone Diet a wholehearted try.

Dr. Barry Sears. Photo: Adam Hunger

What is the Zone diet? After having followed Dr. Sears’ guidelines for some time now, I would sum it up this way: It revolves around fulfilling your daily protein needs (based on lean muscle mass and the amount of physical activity you perform each day). From there, this “protein prescription” is delivered through a series of small to moderate meals throughout the day, with each meal divided up between the major macronutrients in such a way that when you eat your body responds with an ideal and balanced hormonal reaction. In other words, no huge spike in insulin, no wanting to crawl under a table to take nap because you’re sleepy, and with a message sent to the brain that communicates “I’m full.” The protein, carbs and fats that make up these meals, Dr. Sears recommends, should be high in quality—meaning lean meats, fish, fruits and vegetables, nuts and seeds, and using grains, starches and sugars as you might a condiment.

For 15 years I never looked into the Zone Diet because I had been convinced it was another radical diet fad. But a few days into following the diet and I knew that one thing for sure was that it was by no means weird or radical. The only radical thing about it was that I doubt I had never consistently eaten so many fruits and vegetables.

Please check back often as I report more.

FILED UNDER: InsideTri / Nutrition TAGS: /

TJ Murphy

TJ Murphy

T.J. Murphy is a 2:38 marathoner and five-time Ironman finisher. He is the former editorial director of Triathlete Magazine, Inside Triathlon and Competitor Magazine. His writing has also appeared in Outside Magazine and Runner’s World. He recently authored “Inside the Box: How Broke All The Rules, Stripped Down the Gym and Rebuilt My Broken Down Body.”

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