This research will examine the glycaemic and lipaemic responses after consuming a mixed meal similar in carbohydrate content, but differing in fat content. Moreover, this research will assess whether acute postprandial reductions in insulin sensitivity can be offset through increasing the dose of rapid-acting insulin for such meals. Venous blood samples will be collected before and for 6 hours after meals, for the determination of glycaemic and lipaemic responses, as well as metabolite and hormonal parameters. In addition this study will assess the impact of mixed meals and adjusting insulin dose on vascular function and subjective ratings of appetite.