This article presents findings on the long-term impact of health practitioner input to reduce obesity amongst adults with intellectual disabilities. Body mass index (BMI) was measured for an input group (N = 33) and a comparison group (N = 40) 6 years after the input group first received input. Data on BMI were collected at baseline, 6 months, 1 year and 6 years. Mean BMI for the input group reduced steadily over 6 years. Mean BMI in the non-input group rose initially, stabilized and then decreased (although remaining higher than at baseline). The input group demonstrated improvements in obesity levels and lost more weight than the non-input group. However, the differences between groups did not reach statistical significance. This and the improvements in BMI within the non-input group may be due to the relatively small sample size, effect size and the impact of other local initiatives.