About Dr Gary ‘Koala’ Leong


Dr Gary Leong is a paediatric endocrinologist who specialises in treatment of children suffering with obesity and diabetes and its complications. A humane and very real person - not just a medical doctor – Gary loves working with kids and their families to help them work towards and enjoy healthier, happier lives.

Qualifications and experience

For the people who care about letters and places, Gary’s professional qualifications and experience is extensive (and impressive). He is an Associate Professor of Paediatrics at the University of Sydney Nepean Clinical School and Nepean Charles Perkins Research Hub in Western Sydney. He is a Senior Staff Specialist in Paediatric Endocrinology and Diabetes and the Clinical Paediatric Lead in the Nepean Family Metabolic Health Service and the Paediatric Diabetes Service at the Nepean Hospital. He is also in private practice at the Children’s Clinic in Bondi Junction.

Prior to this, for 12 years Dr Leong maintained a joint clinical and research appointment at the Mater Children’s Hospital and Queensland Children’s Hospital (formerly Lady Cilento Children’s Hospital) in Brisbane and The University of Queensland’s Institute for Molecular Biosciences, where he conducted clinical and basic research into child obesity and metabolism.

He obtained a PhD from the Garvan Institute, The University of New South Wales in 2002 after completing his general paediatric and paediatric endocrine training in Sydney and Australia in 1992. His medical degree was obtained from The University of Melbourne in 1982. Dr Leong has memberships of several national and international paediatric endocrine and research societies and was formerly the Chair of the Australasian Paediatric Endocrine Group Growth Hormone Advisory Committee, which assisted the Federal Department of Health by providing expert advice on growth hormone therapy in children with growth problems.

Dr Gary’s driving passions

While Gary’s research has taken him across the globe, from Sydney, Australia to the National Institutes of Health in Bethesda, Maryland, USA, it is his clinical work with children and their families that inspired his work finding practical ways to help families break the cycle of obesity.

Experiencing firsthand the devastating impacts of obesity on families, Gary felt impassioned to find simple and practical ways to support these parents and children to reclaim their lives through sustainable changes that anyone can do, with the right mindset, habits and support. Integrating his personal love of cycling, especially long, challenging rides like Le Tour de France, Gary encourages everyone to get on their bike and stay on it.

Gary rides every year for various charities, but has been a great supporter of the Smiling for Smiddy Cancer charity which supports cancer research in melanoma at the Mater Foundation. More recently he has become a board member of the Fab to Fit Foundation which promotes physical activity programs for children from socially disadvantaged communities where childhood obesity is highly prevalent.


Gary and his wife Micky are proud parents to three now adults. They have a large loving family who migrated here from Hong Kong in the mid 1960s when Gary was only four years old. He is a cycling fanatic and loves combining his passion for cycling with his great loves of travel and connecting with people, especially his family.

Interested in having Dr Gary Leong speak at your next conference or training event? Learn more here.