A Malaysian by birth, Mars moved to the United Kingdom to read medicine at Sheffield University and graduated in 1998, followed by obtaining membership to the Royal College of Paediatrics and Child Health and completing her training in general paediatrics in Manchester. Post completion of training, she undertook further subspeciality training in paediatric endocrinology and a Clinical Research Fellowship in congenital hyperinsulinism, completing a postgraduate research degree at The University of Manchester.

She was appointed as a Consultant Paediatric Endocrinologist at the Royal Manchester Children’s Hospital in 2010, and is currently the clinical lead for the Department of Paediatric Endocrinology and lead clinician for paediatric obesity, disorders of sexual differentiation and has also developed interests in metabolic bone diseases with particular focus on skeletal dysplasias.

In addition to her clinical role, she is actively involved in the training of medical students, junior medical staff and maintains a keen interest in medical research. She has previously held the post of guidelines officer for the British Society of Paediatric Endocrinology and Diabetes (BSPED), is a professor advisor for the NIHR funded obesity empowerment network (OEN) UK and have previously contributed to the development of National Institute of Health and Clinical Excellence (NICE) guidelines for obesity and quality standards.