The Public Health England Learning Disabilities Observatory published some guidance last year that might be of help. The guidance is for public health staff commissioning or running weight management services and other mainstream health professionals working to support people to lose weight. It is also for family carers, social care staff and learning disabilities professionals. It advises about specific aspects of weight management for people with learning disabilities.
It can be found at www.improvinghealthandlives.org.uk/gsf.php5?f=314268