Childhood obesity is a major public health concern which has seen a rapid upward trend since the 1980s. The long-term impact on health is potentially severe as it frequently tracks into adulthood. Comorbidities traditionally associated with adult obesity are now commonly seen in obese children, including cardiovascular disease risk factors, type 2 diabetes, musculoskeletal issues, and respiratory complications such as sleep apnoea and asthma. The Healthy Weight tier 3 weight management service provides a novel specialist programme for obese children and young people (CYP) in Great Yarmouth and Waveney, where obesity prevalence is significantly higher than East of England and national averages. This population group has significant deprivation, and prevalence of behavioural and learning difficulties, which together with difficult family situations are likely to be contributing to increased risk of obesity, as well as presenting barriers to engagement and effective weight management. The multi-component programme follows NICE guidelines (CG43) and is available to all local CYP with BMI >98 percentile for their age (UK90 reference cohort), or >91 percentile with complex needs. The focus is on healthy lifestyle promotion by regular weight measurement, weight management discussion, dietary advice, and physical activity referral. Provision is tailored to each individual, based on specialist clinical assessment. Change in obesity status was assessed at follow-up time points of 3, 6, 9, 12, 18 and 24 months. Standard protocols were used to measure height and waist circumference and a Tanita BC420MA was used to measure total weight and bioelectrical impedence-estimated muscle mass. BMI z-scores were used as the primary outcome measure as recommended by NICE guidance (CG47), with waist-height ratio (WHtR) and fat free muscle index (FFMI), providing more detail of the change in body weight and composition achieved.