OBJECTIVE: To compare effects of a high carbohydrate (high-CHO) and a monounsaturated fat diet (high-MUFA) on body fat distribution and sex hormones in post-menopausal women with Type 2 diabetes. DESIGN: Randomised cross-over with no washout. SETTING: Geelong Hospital outpatient. SUBJECTS: Thirty four women were recruited, 30 completed the study, and data are presented for 21 women compliant to the high-CHO diet. INTERVENTIONS: Women followed a high-CHO diet (20% energy (%E) from fat, 60%E from carbohydrate and a high-MUFA diet (40%E from fat, half as monounsaturated fat, 40%E from carbohydrate) in random order for 12 weeks each. MAIN OUTCOME MEASURES: Dietary compliance was measured by change in linoleic acid (C18:2,omega-6) in plasma cholesteryl esters. Body composition was measured by dual-energy X-ray absorptiometry. Fasting concentrations of glucose and insulin were measured in plasma. Steroid hormones and sex hormone binding globulin (SHBG) were measured in serum. RESULTS: On the high-CHO diet C18:2,omega-6 in plasma cholesteryl esters declined by 5.4% (95% confidence intervals (CI), -2.5% to -8.4%, P=0.0015). Fat was lost mainly from the lower body (lower body loss -0.71 kg, 95%CI, -0.43 to -1.00 kg, P=0.001; upper body loss -0.15 kg, 95%CI, -0.76 to +0.46 kg, P=0.6). Yet on the high-MUFA diet, lower body fat loss was minimal (-0.22 kg, 95%CI, +0.11 to -0.55 kg, P = 0.2). By general linear modelling (GLM), differences in lower body fat loss were significantly related to diet (P = 0.04). After adjustment for age, dehydroepiandrosterone sulphate (DHEAS) concentrations after the high-CHO diet were related to levels of lower body fat (r = 0.394, P = 0.04). CONCLUSIONS: In women with Type 2 diabetes following a high-CHO diet for 12 weeks the disproportionate loss of lower body fat is related to a decline in DHEAS.