Witnessing my father's struggle with Multiple Sclerosis sparked my interest in nutrition. In our efforts to address his disease, we tried a variety of approaches, including healthy foods, targeted supplements, and cutting-edge medications prescribed by his doctor. Yet, none of these proved to be a solution. After he passed away, I realized there must be other underlying factors that are not being addressed.

Over the course of my career, I have independently published fifteen books focused on healthy eating and exercise. However, staying up late working on my computer—driven by a desire to help others—was not the best choice for my own longevity. The artificial light at night disrupted my circadian rhythm, resulting in poor sleep, intense food cravings, and a dependence on caffeine. Despite eating well and exercising daily, I also developed a blood clot in my left leg. Looking back, I realized I always carried my cell phone in my left pant pocket. Coincidence or not, I found myself—a 40-year-old fitness enthusiast—taking blood-thinner medication typically prescribed for older adults. For me, diet and exercise alone were not enough. There must be other, non-caloric factors contributing to dysfunction. People shouldn’t be experiencing serious health issues in their 30s and 40s as frequently as they do.

Imagine dedicating your life to diet and exercise, only to one day realize that much of what you learned was incomplete—or even misleading. In my search for answers, I encountered the groundbreaking work of neurosurgeon Dr. Jack Kruse, which he discussed in a compelling interview with Rick Rubin and Andrew Huberman. Dr. Kruse’s approach offers a unique perspective on circadian biology. Unlike most health professionals that focus primarily on biochemistry, Dr. Kruse emphasizes biophysics as the foundation. By recognizing how your biological rhythms align with your surroundings, you can uncover deeper insights into sustaining optimal health.

Circadian biology explores how your metabolism is influenced by the natural cycles of light and darkness. By aligning your daily habits with these rhythms, you can enhance brain function and support overall well-being. Effectively managing your circadian biology is crucial for maintaining health and longevity. In today’s modern world—where artificial light and wireless pollution are widespread —simply eating well and exercising is no longer enough.

Circadian biology has only recently been fully understood, so there’s no need to feel discouraged by our earlier misconceptions. For example, in the 1980s, the concept of the glycemic index was groundbreaking, measuring how quickly carbohydrates raise blood sugar levels. However, it wasn’t until 2016 that researchers began to recognize the “glycemic index” of light and its impact on our biology.

Research shows that artificial blue light can raise blood sugar levels, while exposure to red light can lower blood sugar by nearly 30%. This suggests that what passes through your eyes—your light environment —may have a greater impact on your metabolic health than what passes through your mouth.

I created the SunDiet™ to educate those unfamiliar with circadian science—a discipline that can take years to master independently. By aligning your body with the natural light and dark cycles, reducing exposure to unseen pollution, and eating properly, remarkable changes can occur. You will sleep more soundly, feel better, look younger, and think more clearly. The SunDiet™ emphasizes that many health problems originate from inadequate sun exposure, excessive use of technology, and poor food choices, which together create dysfunction.

The SunDiet™ book shares the improvements I’ve made by applying circadian principles inspired by Dr. Jack Kruse and other innovators in the field. Since everyone’s environment is unique, your personal situation may require customized solutions. Always conduct your own research to determine what works best for your specific circumstances.

NUTRITION CERTIFICATIONS

  • Certified 40/30/30 Nutritionist, 1999

  • Certified Zone Diet Instructor, 2002

FITNESS CERTIFICATIONS

  • NASM (National Academy of Sports Medicine)

  • NFPT (National Federation of Professional Trainers)

  • FMS (Functional Movement Systems)

  • TRX (Suspension Training)

EXPERIENCE

  • Nutritionist for the Zone Diet Delivery Service -New York, Chicago, and Los Angeles

  • Dietetic Technician, Central Suffolk Hospital – Riverhead, N. Y.

  • Nutritionist and Trainer, Core Dynamics Gym – Water Mill, N.Y.

  • Nutrition consulting, Ross School Tennis Academy – East Hampton, N.Y.

  • Nutrition consulting, West Hampton Hurricanes football team

  • Director of the Parisi Speed School, Setauket, N.Y.

  • Special guest Nutritionist on “The Culinary Experience” with chef Michael Mosolino

  • Guest lecturer at the Fight Breast Cancer for Women at South Hampton High School

CURRENT FOCUS

  • My current focus is to investigate the non‑calorie forces that affect our health, beyond the familiar prescriptions of diet and exercise.

A man sitting at a wooden desk in front of a bookcase filled with books. He is smiling, wearing a light gray SunDiet shirt, and sitting in a black leather chair.

John Erickson