Objective To determine the extent to which intensive dietary intervention can influence glycaemic control and risk factors for cardiovascular disease in patients with type 2 diabetes who are hyperglycaemic despite optimised drug treatment.Design Randomised controlled trial.Setting Dunedin, New Zealand.Participants 93 participants aged less than 70 years with type 2 diabetes and a glycated haemoglobin (HbA1c) of more than 7% despite optimised drug treatments plus at least two of overweight or obesity, hypertension, and dyslipidaemia.Intervention Intensive individualised dietary advice (according to the nutritional recommendations of the European Association for the Study of Diabetes) for six months; both the intervention and control participants continued with their usual medical surveillance.Main outcome measures HbA1c was the primary outcome. Secondary outcomes included measures of adiposity, blood pressure, and lipid profile.Results After adjustment for age, sex, and baseline measurements, the difference in HbA1c between the intervention and control groups at six months (−0.4%, 95% confidence interval −0.7% to −0.1%) was highly statistically significant (P=0.007), as were the decreases in weight (−1.3 kg, −2.4 to −0.1 kg; P=0.032), body mass index (−0.5, −0.9 to −0.1; P=0.026), and waist circumference (−1.6 cm, −2.7 to −0.5 cm; P=0.005). A decrease in saturated fat (−1.9% total energy, −3.3% to −0.6%; P=0.006) and an increase in protein (1.6% total energy, 0.04% to 3.1%; P=0.045) in the intervention group were the most striking differences in nutritional intake between the two groups.Conclusions Intensive dietary advice has the potential to appreciably improve glycaemic control and anthropometric measures in patients with type 2 diabetes and unsatisfactory HbA1c despite optimised hypoglycaemic drug treatment.Trial registration Clinical trials NCT00124553.

Glycaemic responses following ingestion of glucose and several rice varieties are appreciably greater in Chinese compared with Europeans, suggesting the need to review recommendations regarding dietary carbohydrate amongst rice-eating populations at high risk of diabetes.

BackgroundGlycemic index (GI) is intended to be a property of food but some reports are suggestive that GI is influenced by participant characteristics when glucose is used as a reference.ObjectiveTo examine the influence of different reference foods on observed GI.DesignThe GIs of five varieties of rice and a sugary beverage (LoGiCane™) were tested in 31 European and 32 Chinese participants using glucose or jasmine rice as reference foods. The GIs of two ready-to-eat breakfast cereals (Kellogg’s cornflakes and Sustain) were tested in 20 younger and 60 older people using glucose or Sustain as reference foods.ResultsThe GIs of rice tended to be higher in the Chinese compared with the Europeans when glucose was used as a reference (jasmine 80 vs 68, P = 0.033; basmati 67 vs 57, P = 0.170; brown 78 vs 65, P = 0.054; Doongara 67 vs 55, P = 0.045; parboiled 72 vs 57, P = 0.011). There were no between-group differences in GI when jasmine rice was the reference. The GIs of breakfast cereals tended to be lower in younger compared with older groups (cornflakes 64 vs 81, P = 0.008; Sustain 56 vs 66, P = 0.054). There was no between-group difference in the GI of cornflakes when Sustain was the reference (cornflakes 115 vs 120, P = 0.64). There was no ethnic difference in GI when glucose was the reference for another sugary food (LoGiCane™ 60 vs 62; P = 0.69).ConclusionsA starchy reference may be more appropriate than a glucose beverage when attempting to derive universally applicable GI values of starchy foods.Trial registrationThe Chinese/European trial is registered with the Australian New Zealand Clinical Trials Registry as ACTRN12612000519853.