The Hernried Center Team offers the Sacramento area unsurpassed weight loss results.

Here at The Hernried Center for Medical Weight Loss, we view obesity – and being overweight in general – as a complex, chronic medical problem that requires a medical solution. The solution we offer has been continually refined for over 30 years, and is proven to be highly effective. Designed by our experienced president and medical director, John Hernried, MD, FACP, our weight loss programs offer comprehensive support for all types of people who suffer from a variety of weight disorders.

Meet Dr. John Hernried, our compassionate, experienced medical director.

Dr John Hernried
President & Medical Director

Dr. Hernried has personally helped over 2,000 people lose weight and live healthier lives in the Sacramento area and beyond. As someone who has struggled with his own weight, Dr. Hernried feels great empathy for those he treats, who have often tried to lose weight numerous times and yet remain unsuccessful — sometimes even after bariatric surgery. To help fight the growing obesity epidemic and give people the healthier, thinner lives they desire, Dr. Hernried has dedicated his practice to offering a scientific, effective and permanent weight loss solution.


Board-Certified: Internal Medicine

Diplomate: American Board of Obesity Medicine

Fellow: American College of Physicians


  • The Gold-Headed Cane Award, Texas Tech School of Medicine, awarded to the individual who best exemplifies the attributes of an outstanding practitioner
  • Sacramento Magazine “Top 200 Doctors”
  • Davis Enterprise “Top Doctors”
  • Solano Magazine Top Doctors in Weight Management


Our medical team sets the standard for excellence in obesity care.

The medical team at The Hernried Center for Medical Weight Loss offers years of specialized experience helping the overweight and obese of the Sacramento area. Each doctor and nurse practitioner was trained by Dr. John Hernried himself and upholds the values of excellence and patient-oriented care that we’re known for.

Sharon Ball, MD

Sharon Ball

Assistant Medical Director

Dr. Ball grew up in the Chicago suburbs and has worked in a variety of inpatient and outpatient settings during her career. She is passionate about helping patients achieve a healthy weight, physical fitness, a wholesome relationship with food, and a reversal of their cardiovascular risk factors. In her spare time, she enjoys reading, gardening, traveling and the company of her family and friends.

Board-Certified: Internal Medicine, Geriatric Medicine

Residency: Internal Medicine, Letterman Army Medical Center, San Francisco, CA

MD: University of Illinois, College of Medicine, Chicago, IL

BS: Biology, cum laude, DePaul University, Chicago, IL

Professional leadership positions:

  • Assistant Medical Director, The Hernried Center, 2004-present
  • Brigade Surgeon, US Army, Germany, Persian Gulf War, 1990-1991
  • Teaching Staff, Internal Medicine Residency Program, Letterman Army Medical Center, 1989-1992


  • Honors Program Graduate, DePaul University, Chicago, IL
  • Health Professions Scholarship Recipient, Army Medical Corps
  • Army Achievement Medal, Operation Desert Storm

Rajinder Trewn, MD

Rajinder Trewn Hernreid

Medical Doctor

Dr. Trewn has been in clinical practice for the past 21 years. Prior to joining The Hernried Center, she spent several years working in primary care, holding numerous positions in a variety of settings, including inpatient, outpatient, nursing home, urgent care, women’s health and many more. She most recently worked as a staff internist with the US Department of Veterans Affairs. From her many years spent treating chronic medical conditions, Dr. Trewn has seen the devastation obesity can have on one’s health. This experience motivates her to help people safely lose weight, and then keep it off for a lifetime. Her patients appreciate her attentive listening and easygoing personality. In her spare time, Dr. Trewn loves to volunteer in the community, take walks with friends, and travel with family.

Board-Certified: Internal Medicine

Diplomate: American Board of Obesity Medicine

Residency: Internal Medicine, State University of New York, Buffalo, NY

Post-Doctoral Scholar: Nutrition and Lipid Lab, University of California Davis, Davis, CA

MD: Christian Medical College, Punjab, India

Arline Yen, MD

Arline Yen Hernreid

Medical Doctor

Dr. Yen was previously in private practice as a general endocrinologist in Dallas, Texas, where she was involved with the care of many patients with diabetes. She is pleased to be a member of The Hernried Center’s multi-disciplinary team. She is dedicated to helping people achieve healthier weights in order to halt the development and reverse the progression of obesity-related diseases, such as diabetes, hypertension, heart disease, and sleep apnea. In her free time, Dr. Yen enjoys playing the piano, attending her children’s sporting events, and spending time with extended family.

Board-Certified: Internal Medicine, Endocrinology

Fellowship: Diabetes and Endocrinology, Scripps Clinic and Research Foundation, La Jolla, CA

Residency: Internal Medicine, University of San Diego Medical Center, San Diego, CA

MD: University of Texas Southwestern Medical School, Dallas, TX

BS: Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA


  • Southwestern Medical Foundation Scholarship
  • Tau Beta Pi, National Engineering Honor Society
  • Phi Beta Kappa, National Honor Society

Dean Tomlin, MD

Dean Tomlin Hernreid

Medical Doctor

Dr. Tomlin was born and raised in Sacramento. After completing his residency, he worked in family practice for a number of years, treating babies, adults and geriatrics. With a growing need for weight management expertise, he switched his area of specialty to bariatrics. Dr. Tomlin is married with two young boys. Outside of work, he is heavily involved with youth basketball. His other interests are family, raising alpacas, biking, youth sports and coaching.

Board-Certified: Family Practice

Diplomate: American Board of Obesity Medicine

Residency: Co-Chief Resident, Family Practice, Sutter Family Practice Residency Group, Sacramento, CA

MD: George Washington University, School of Medicine, Washington, DC

BS: Kinesiology, Psychology, University of California, Los Angeles, Los Angeles, CA

Member: American Academy of Family Physicians, American Society of Bariatric Physicians, The Obesity Society, American College of Sports Medicine, California Academy of Family Physicians


  • Chancellor’s Service Award for Community Service, University of California, Los Angeles, Los Angeles, CA

Diane M. O’Laughlin, FNP-BC

Nurse Practitioner

Dean Tomlin Hernreid

Diane obtained her Masters as a Family Nurse Practitioner from California State University, Sonoma. She has worked as a nurse practitioner in primary care medicine since 2012. She has always had a passion for helping patients manage their weight, and after losing weight as a client with the Hernried team, Diane decided the time was right to specialize in weight management, and joined Hernried team as a nurse practitioner. Diane is currently pursuing her doctorate at California State University, Fresno, focusing on the interdisciplinary team approach to weight management and the impact of weight loss on the blood sugar levels of type II diabetics. Diane enjoys singing well, playing the piano passingly, traveling broadly, and prefers the chocolate pudding meal replacement above all others.

Board-Certified: ANCC Family Nurse

PractitionerMember: The Obesity Society, Sigma Theta Tau, Zeta

Residency: Co-Chief Resident, Family Practice, Sutter Family Practice Residency Group, Sacramento, CA

EtaAwards: Mercy McAuley Award Air Force Leadership Award Rotary International Foundation Award

Lori Arguello, NP

Lori Arguello Hernreid

Nurse Practitioner

Lori earned her Bachelor of Science in Nursing from California State University, Sacramento in 2004. She then went to work as a registered nurse in cardiac, trauma, and surgical critical care settings. Later, she attended the University of Illinois at Chicago where she graduated with her Master of Science in Nursing in 2009. Her master’s project, Evaluation of an Advanced Practice Nurse – Managed Diabetes Clinic for Veterans, was published in The Journal for Nurse Practitioners July/August 2010 edition. From 2010 to 2015, she worked in a cardiology group in both inpatient and outpatient settings. Lori is passionate about preventative care, nutrition, and empowering patients to take control of their health. Along with cardiology and obesity, she also has interest in treating diabetes. Lori’s hobbies include running, world traveling, reading, cooking, and shopping at Nordstrom.


Shelly Rodgers, NP

Nurse Practitioner

Drawing on her thorough foundation in nutrition, Shelly loves educating people about the health benefits of eating well, including disease prevention and overall well-being. Practicing at The Hernried Center has given her the opportunity to make a real difference in people’s lives, and she feels immense satisfaction when sees improvement. As a caregiver, she always tries to work with people to pinpoint their needs and offer the care that will best benefit their life. She graduated with honors from Columbia University’s School of Nursing, and patients and staff value her for her knowledge and helpful attitude.


Rosemarie Alpay, NP

Rosemarie Alpay, NP

Nurse Practitioner

As a certified people-person, Rosemarie loves partnering with patients to help them along their weight loss journey. She views herself as a facilitator and a cheerleader, and always makes decisions with patients, rather than for them. Rosemarie has had her own struggles with weight, which gives her the empathy that has been crucial to her success as a caregiver. She received her Master of Science in nursing from University of California, San Francisco, has 35 years of nursing experience, and is also a Zumba instructor.



Amber D. Briner, NP

Nurse Practitioner

Graduating with a Bachelor of Science in Nursing from the University of Indianapolis in 2004, Amber worked as a registered nurse for several years, primarily in hospital cardiac units. She cared for many patients whose conditions could have been vastly different if interventions to their health had been made sooner. From that experience, Amber knew that she wanted to work in a medical setting that would give her the platform to help patients implement changes to improve their health before developing more serious conditions. Her personal experience with a family member’s struggle with obesity and related health consequences adds to the understanding she brings to medical weight loss. Amber earned her Master of Science in Nursing from the University of California San Francisco in 2012. She has also served as a clinical nursing instructor and worked as a nursing volunteer in several places including Haiti. Amber enjoys spending time hiking, kayaking, and camping with her family and two children.

Lisa Tami, RD

Lisa Tami Hernreid

Lead Dietitian & Behavioral Health Educator

Lisa holds a Bachelor of Science degree in dietetics from California State University, Sacramento and completed her dietetic internship with the California Department of State Hospitals in Napa. Her background includes 16 years of clinical dietetics and behavioral health education. Lisa earned her Level I and II Certificates for adult weight management through the Academy of Nutrition and Dietetics. She enjoys teaching people the behavioral skills they need to successfully transition from weight loss to long-term weight maintenance. Lisa is a proud mom of two terrific kids, a chauffeur to kids’ sporting events and a Girl Scout leader. Lisa says, “I enjoy kayaking, camping, yoga, and Zumba, but my favorite place of all is to be on a hiking trail with my family.”

Louise Crawford

Louise Crawford Hernreid

Managing Behavioral Health Educator

Louise joined us after teaching writing, working at home as a published novelist, and being a “most of the time” stay-at-home mom. Prior to parenting, she received her master’s degree in psychology, specializing in addictions and recovery. Regarding weight issues, Louise says, “I gained 62 pounds when I was pregnant, it took two years to lose it, and I have kept it off for 15 years. I’m excited to help others achieve and maintain their weight loss goals and live the life they want to live.”


Perri Tanner

Perri Tanner Hernreid

Behavioral Health Educator

Perri Tanner received a Bachelor of Science in psychology from Brigham Young University. Perri was delighted to join The Hernried Center after a 26-year career working in adult education, developing programs and teaching adults with a variety of disabilities and health challenges. Perri’s passion is helping people discover and master the skills and behaviors they need to live the healthiest life possible. Perri has struggled with weight management most of her adult life, which gives her insight and compassion to share with others on their path to a healthier life. In her free time, she loves being with her family, hiking, taking Zumba classes and volunteering at her church.


Janine Thomas, RD

Janine Thomas Hernreid

Behavioral Health Educator

After graduating from the University of California, Santa Barbara with a Bachelor of Arts in communication and working in commercial insurance for a decade, Janine discovered nutrition was her true passion. She went back to school and graduated from Sacramento State University with a Bachelor of Science in dietetics. After completing a dietetic internship through Oakwood University in Huntsville, Alabama, she earned her registered dietitian credential in 2013. Her first job as a dietitian was providing clinical nutritional care for the elderly population and overseeing food service management. However, after two years she realized that her true interest was in obesity treatment and prevention. Finally, Janine feels like she is in the right place at The Hernried Center. In her free time, she enjoys running, cooking, traveling and spending time with family.

Donna Ruden, RD

Donna Ruden Hernreid

Behavioral Health Educator

Donna completed her Bachelor of Science in dietetics at California State University, Sacramento and completed her dietetic internship at the University of California, Davis Medical Center in Sacramento. Donna earned her Level I Certificate of Training in adult weight management through the Academy of Nutrition and Dietetics. Her background includes a Bachelor of Science in business administration and she previously worked for Hewlett-Packard for 17 years before making a career change into the field of nutrition and dietetics. Donna truly enjoys collaborating with people along their journey toward a healthy life. She enjoys being in nature, exercise, yoga, cooking, volunteering and spending time with her family.

Amanda Loza

Amanda Loza Hernreid

Behavioral Health Educator

A graduate of San Francisco State University’s health sciences program, Amanda studied health education while also interning at the San Francisco Department of Public Health (SFDPH) under the guidance of SFDPH’s head dietitians. An experienced youth educator, Amanda developed bilingual (Spanish/English) curricula for school-aged children in the San Francisco Bay Area that covered health, fitness and nutrition. She is a former fitness instructor who enjoys Latin dance and Zumba, but now most of her time outside of work is spent raising her two young daughters.


Carmelita Lombera

Behavioral Health Educator

Carmelita Lombera joined The Hernried Center team in November 2016 and has already made a significant impact in the lives of her patients. With a Bachelor of Science degree in Nutrition-Dietetics from the University of California, Berkeley, Carmelita’s patient interaction focuses on guiding every individual through their unique weight loss journey to help them effectively achieve their goals. Carmelita finds her position truly rewarding when she can give patients the tools they need to meet their personal goals, as well as help them grow stronger and lead longer, more fulfilled lives. Her firsthand experience includes working as a health coach, weight loss consultant and fitness coach, so she understands the physical, emotional and mental challenges associated with weight loss. She strives to always provide the highest level of care and facilitate an open, honest and positive line of communication with every patient.

Jessica Hamon, MPH

Behavioral Health Educator

Jessica earned her Bachelor of Arts degree in molecular and cell biology with minors in ethnic studies and Spanish at University of California, Berkeley. She completed her Master’s degree in public health in the field of social and behavioral sciences at Yale University School of Public Health. After completing two years of medical school at University of California, Davis, Jessica joined The Hernried Center so she could provide more patients with one-on-one health education. Jessica has led smoking cessation research and behavior modification, worked with breastfeeding mothers in disadvantaged, Spanish-speaking areas, and assisted with healthcare, education and development in rural Panama. These experiences have strengthened Jessica’s drive to improve the health and well-being of her clients. When not working with clients, Jessica enjoys hiking with her dog, Jojo, and competing in her fantasy sports leagues, always cheering for the Cal Bears.

Jennae Lambdin, M.Ed.

Behavioral Health Educator

Jennae returns to the Hernreid Center as a behaviorist. She first began as a behaviorist in 2009 and worked for a 1 ½ before transitioning into an affiliated weight loss program in Stockton, Pacific Medical Weight Loss. Jennae holds a Bachelor degree in Communicative Disorders and a Masters in Special Education. She has been a long tine coach and fitness trainer who is passionate about motivating and encouraging people in the area of behavior change, health and wellness. “The opportunity to help people develop and retain skills towards a quality of life in regards to health and wellness is a blessing and privilege”. Jennae currently teaches at San Joaquin Delta College in the Kinesiology Department. She has been teaching at the community college for 30 years. She enjoys everything ‘sports and outdoors’. My favorite past times include golfing, hiking, having coffee with friends, family time and running with my dogs, Jesse and Aliza.

Stacey Volcy, M.P.H.

Behavioral Health Educator

Stacey currently holds a Bachelor’s of Science in Biology and a Masters in Public Health. While earning her Master’s degree in Public Health at Florida International University, Stacey became a middle school science teacher. It was at that time that her interest in chronic disease related to obesity developed. She also completed an internship at the Florida Health Department in Epidemiology, and taught Public Health college courses as an Adjunct professor at Nova Southeastern University. Stacey’s passion for public health drove her to venture into the non-profit sector, where she helped with the effort of implementing the Affordable Care Act in South Florida which helped bridged the health insurance gap for thousands of consumers in the area. Stacey and her family moved to Sacramento in the summer of 2017 where she joined the Henried Center shortly after. She enjoys being part of a team of professionals who help patients achieve their goals of becoming healthier. Stacey enjoys spending time with her family, and her dream is to travel the world with them. Stacey also enjoys a good vampire vs. werewolf movie, is an avid fan of J.K Rowling, and reading.

Christian Zamora, CSCS

Christian Zamora Hernreid

Exercise Physiologist

Christian attended California State University, Sacramento’s kinesiology program and graduated with a concentration in exercise science. He has done many things in the health and fitness arena, from managing one of the largest regional personal training departments in Sacramento to volunteering at retirement homes providing group exercise classes. His greatest passion is teaching and making genuine connections with people by helping them realize their true potential. Christian loves working at The Hernried Center because they don’t “band-aid” problems, but instead empower people by helping them achieve lifelong health through education and support. In his personal life, Christian’s passions are his faith, family and learning new forms of exercise and activity.

Loren Belcher

Exercise Physiologist

Exercise Physiologist Loren Belcher comes to us with extensive experience and a passion for helping others live healthy, active lives. With a Bachelor of Science degree in Kinesiology from California State University, Sacramento, and his experience working as a fitness manager and yoga instructor, he understands the struggles that accompany obesity and weight loss. Loren caters his care to the unique needs of each patient and provides the tools they need for long-term success. Working with you through every step of your journey, he can help you meet your goals and achieve lasting results.


Max Polin, M.S.

Exercise Physiologist

Max attended California State University, Sacramento and graduated with a concentration in exercise science. He is a passionate athlete with over 15 years of coaching experience and strives to demystify “exercise”, shaping it to feel more attainable as a lifestyle. With a background in both athletics and clinical weight management, he understands the demands of weight control and fitness goals. Through class meetings and personal appointments, he will walk the journey with you to achieve a lifetime of success.


Real stories from people in the Sacramento area who succeeded at The Hernried Center.

We have given thousands of people new, thinner lives, and many have given us some kind words in return. As you’ll see, our program worked for them when nothing else did, and we couldn’t be happier.

For more information about The Hernried Center, call 800-815-4881. You can also request a free phone consultation by using our easy online form.