To determine the prevalence of clinical eating disorders and lesser degrees of disturbed eating in young adults with insulin dependent diabetes and a matched sample of non-diabetic female controls. Cross sectional survey of eating habits and attitudes in diabetic and non-diabetic subjects. Outpatient clinic catering for young adults with diabetes; community sample of non-diabetic women drawn from the lists of two general practices. 100 patients with insulin dependent diabetes (54 women and 46 men) aged 17-25 and 67 non-diabetic women of the same age. Eating habits and eating disorder psychopathology were assessed by standardised research interview adapted for the assessment of patients with diabetes (eating disorder examination). Glycaemic control was assessed by glycated haemoglobin assay. In both non-diabetic and diabetic women disturbed eating was common, and in diabetic women the degree of disturbance was related to control of glycaemia. Twenty of the diabetic women (37%) had omitted or underused insulin to influence their weight. This behaviour was not restricted to those with a clinical eating disorder. None of the men showed any features of eating disorders, and none had misused insulin to influence their weight. There was no evidence that clinical eating disorders are more prevalent in young women with diabetes than in non-diabetic women. Nevertheless, disturbed eating is common and is associated with poor control of glycaemia, and the misuse of insulin to influence body weight is also common in young women with diabetes.