Our Team

Dr. Derek (Owner)

Dr. Alessi - Headshot
Dr. Derek Alessi

Derek Alessi, PhD (Dr. Derek™) became interested in the field of fitness training at an early age when he was an obese teenager.  Determined to change his health, body and ultimately his future, he began strength training and developed a system to modify his nutrition.  Derek dropped over 80-pounds in one year and later that same year, he entered his first and only body building contest. Disenchanted with the way body building tends to minimize health and well-being in order to encourage raw size, he left that arena and dedicated his career to helping individuals achieve better health and wellness through a program of planned exercise and practical nutrition. At the age of 19, Derek passed a national fitness certification exam and began his career in personal fitness training.  He furthered his quest for more information through education and received post-graduate degrees in health and physical education as well as a master’s degree in nutrition.

As America’s Premier Health Advocate Dr. Derek’s core belief is that health and fitness are not a result of gimmicks, hype or the latest butt buster. Instead they are achieved by understanding the physiological complexities of the body and the synergistic role that the right kinds of exercise along with supportive nutrition can play in unlocking the healthy body that is inside every one of us.   

Dr. Derek is passionate about body fat reduction, medication reduction and help individuals improve the quality of their lives.  His practices incorporates: glucose, ketone, body fat and deep sleep tracking along with the right kind of diet and intelligent exercise to extend life and improve lifestyle.

Dr. Derek is the author of The Bermuda Triangle Diet (October, 2009 Strategic Publishing), Lose Fat Forever (2003), and The Promise Health and Fitness System (2002 ).  Derek has earned a doctorate degree in health and physical education and a master’s degree in nutrition.  He is also a National Strength and Conditioning Association (NSCA) trainer.  He owns and operates Dr. Derek Health & Fitness, a private practice, a personal training facility for adults and a facility for children in East Amherst New York.  He has appeared on over 2100-TV and 400-radio programs throughout the country and has been featured in national print media including Maxim, Burn Fitness for Women and Iron-Man Magazines.

Dr. Derek is a health, fitness and lifestyle contributor for the USA Today and the host of weekly TV show on NBC Cleveland & NBC in Buffalo, New York called Live It Fit Now!  In addition, Dr. Derek conducts regular health and fitness seminars for the health care industry, Fortune 1000 companies, and small businesses where he combines his unique brand of humor, empathy and knowledge to communicate his positive, affirming message:  Make the Most of Your Life… Live It Fit!™

Calvin de Zitter (General Manager)


Calvin de Zitter, born in South Africa, has been involved in the field of Health and Fitness since 2005. He attended Nelson Mandela Metropolitan University, Port Elizabeth, and has a 5 year Honors degree in Biokinetics ( Athletic training) and is registered under the Health Professions Council of South Africa (HPCSA). He specializes in Orthopedic examination and final phase rehabilitation and has worked with many patients ranging from the elderly to elite athletes, Parkinson’s patients, stroke victims and more. 

After obtaining his degree, Calvin decided to take his knowledge abroad from his studies in South Africa to get first hand experience helping others on cruise lines. He managed and trained passengers on Royal Caribbean Cruise lines for over two years, traveling to over 30 countries. 

Calvin then immigrated to Buffalo, New York, where he has been a committed staff member at Dr. Derek Health and Fitness since 2012. His  focus has been on training and managing clients who are passionate about making life changes in fitness and nutrition. 

He is an avid road cyclist and is a field hockey club coach in Buffalo.