The primary measurement in the study will be the glycaemic response. This will be measured using finger-prick blood samples. The fingers in the non-dominant hand will be used. To encourage blood flow the hand will be warmed using warm water or a hot towel beforehand if required. The finger will then be disinfected using a sterile wipe. Blood will be obtained by finger prick using a single-use lancing device. To minimise plasma dilution fingertips will not be squeezed to extract blood but gently massaged starting from the base of the hand moving towards the tips. The first two drops of expressed blood will be discarded and the next drop (5 μL) will be used for testing. Blood glucose in the sample will be measured using the HemoCue® 201+ Glucose analyser (HemoCue Ltd, Dronfield, UK).