The protein, fat and carbohydrate composition of diets can modify heart function abnormalities associated with insulin resistance (when cells in the muscles, fat, and liver do not respond well to insulin and cannot easily take up glucose from the blood) and therefore reduce the risk of diabetes. The aim of the study was to examine the effect of a reduced carbohydrate diet that was high in both protein and dietary fibre on insulin sensitivity and insulin secretion in overweight and obese women at risk of diabetes, independent of weight loss. The study is a randomised control trial which recruited 89 women at risk of diabetes. The participants were randomly assigned to either a standard diet or a relatively high protein and fibre diet group for a period of 10 weeks. Results indicate that a modest increase in consumption of dietary protein and fibre, without emphasis on energy reduction, improved several cardiometabolic risk factors in overweight women. There were modest reductions in body mass, total body fat and central body fat, without loss of lean mass and improvements in total serum and low-density lipoprotein cholesterol levels. Authors conclude that the heart function benefits achieved with moderate increases to fibre and protein, support the use of this dietary approach for overweight individuals at risk of diabetes.