Johns Hopkins All Children's Hospital

Meet Our Team

Our team of pediatric obesity specialists work in both clinical and community settings to provide families with the tools to build healthier lifestyles.

Pediatric Medicine

Raquel Hernandez, MD MPH Pediatric Medicine

Dr. Hernandez is assistant professor of pediatrics at the Johns Hopkins University School of Medicine and medical director of the Johns Hopkins All Children’s Healthy Weight Initiative. She completed her medical school, residency and fellowship training at the Johns Hopkins University School of Medicine. She additionally completed a Master in Public Health with an emphasis on nutrition at the Johns Hopkins Bloomberg School of Public Health during her fellowship in general academic pediatrics. As medical director of the hospital’s Healthy Weight initiative, Dr. Hernandez has developed and grown innovative and evidence-based approaches to promote healthy lifestyles that target the current pediatric obesity epidemic within our institution and our community. As one of few pediatricians certified in obesity-medicine nationally and regionally, she has led a multidisciplinary weight management clinic, Healthy Steps, based at Johns Hopkins All Children’s since 2012. With the support of her interprofessional team, the Healthy Steps clinic has provided tailored, patient-centered recommendations to children ages 0-21 years of age who have weight-related medical issues, including low self-esteem, anxiety/depression, hypertension, elevated cholesterol, diabetes and other health conditions. She also has been an ongoing advocate for reducing weight-related stigma within the health care setting as well as within schools. By engaging with community partners including our community division and school-based health clinics, exciting new community-based programs including Health Squads, the First Steps/Fit4Allkids Program and Fit4Allteens Program have continued to engage at-risk children in the Tampa Bay region while connecting them to the outstanding specialty care provided by Johns Hopkins All Children’s for those requiring additional medical care.
Publications by Raquel
View Raquel’s Bio


Dianna Boone, Ph.D.

Dianna Boone, Ph.D. Psychology Fellow

Dianna Boone is a pediatric psychologist in the Johns Hopkins All Children’s Institute for Brain Protection Sciences. As part of the Johns Hopkins All Children’s Healthy Weight Initiative, Dr. Boone sees patients in the Healthy Steps clinic and provides weekly outpatient therapy to patients with weight management concerns. She also provides weekly outpatient therapy to patients with anxiety, depression, and adjustment disorders. Dr. Boone’s research interests include identifying parenting and family practices associated with youth weight status and other chronic illness factors. Her interests also include developing and disseminating evidence-based interventions to improve children’s healthy lifestyle behaviors and adherence. Dr. Boone earned her Ph.D. in clinical psychology from Texas Tech University in Lubbock, Texas. She completed a pediatric psychology internship in the Department of Clinical and Health Psychology at the University of Florida and a combined clinical/research postdoctoral fellowship in pediatric psychology at Johns Hopkins All Children’s Hospital.


Melanie Newkirk, D.C.N., R.D.N., C.S.P., L.D.

Melanie Newkirk, D.C.N., R.D.N., C.S.P., L.D. Clinical Nutrition Manager

Melanie Newkirk, D.C.N., R.D.N., C.S.P., L.D. is a Registered Dietitian/Nutritionist and currently serves as Clinical Nutrition Manager for Nutritional Services and Lactation at Johns Hopkins All Children’s Hospital. She earned her Doctor of Clinical Nutrition from Rutgers School of Health Professions and is also a Certified Specialist in Pediatric Nutrition. She has more than 25 years of experience working with families in the clinical and community settings in the field of weight management. She is the lead instructor for the Fit4Allkids programs. Her research interests focus on the early origins of growth influenced by maternal health in pregnancy and nutrition during infancy. She believes in a family centered approach recognizing that developing healthy habits must be individualized to the needs of the parents and children who attend Healthy Steps Clinic or attend our community programs. The most rewarding part of her job is seeing families who make positive lifestyle changes with the help of our team.
Publications by Melanie

Samantha Toffoli, D.C.N.

Samantha Toffoli, D.C.N. Registered Dietitian

Samantha Toffoli is a registered dietitian with Johns Hopkins All Children’s Healthy Weight Initiative. She joined the hospital staff in 2021. She received her bachelor’s degree in Dietetics at the University of Florida, followed by a master’s degree from Arizona State University, where she completed a year-long traineeship funded by the Maternal and Child Health Bureau. This program focuses on developing skills to increase knowledge and leadership in the field of public health nutrition related to maternal and child health. Her research interests include the use of appetite awareness strategies in the pediatric population, eating disorders related to food insecurity, and the social determinants of childhood obesity.
Publications by Samantha

Articles from our team: Nutrition and Pediatric Obesity

Hidden Sugars: How to Take the Mystery Out of Making Healthier Choices for You and Your Child

Raquel Hernandez, M.D., M.P.H., medical director of the Healthy Weight Initiative, talks about how to reduce sugar intake in our children’s diets.

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Confronting the Impact of COVID-19 on Children and Families Using a Research Focus on the Social Determinants of Health

Physician researchers at Johns Hopkins All Children’s Hospital and their collaborators have embarked on an innovative research study designed to understand the social, economic and health impact of the COVID-19 on families in the Tampa Bay area.

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What Parents Need to Know about Childhood Obesity

Raquel Hernandez, M.D., discusses childhood obesity and some tips for families on maintaining a healthy lifestyle.

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Could Your Healthy-Weight Child Be at Risk for Obesity?

A recent study by researchers at Johns Hopkins All Children’s Hospital shows that when it comes to counseling for weight management, pediatricians and parents may be neglecting healthy-weight kids.

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Hypertension in Adolescents

Even though hypertension is more common in adults, certain risk factors can cause high blood pressure in teens. Jasmine Reese, M.D., explains what parents should know about hypertension in teens.

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