Dietary patterns were reviewed and correlated with the patients' clinical details in 252 patients seen at the initial visit to a diabetic clinic of a major metropolitan teaching hospital. Except in the subgroup of male patients with insulin-dependent diabetes, there was an extremely high prevalence of obesity, especially in females (70% greater 120% of standard weight; 28% greater than 150%). Traditional 'low-carbohydrate' diets were commonly found irrespective of ethnic origin, particularly in those individuals who had received previous dietary education. This study highlights the urgent need for public health education programmes in order to try to prevent the development of obesity since therapy remains unsatisfactory once it is established.