Effect of lupin enriched biscuits as substitute mid-meal snacks on post-prandial interstitial glucose excursions in post-surgical hospital patients with type 2 diabetes

Brief name: Controlled cross-over intervention study that examined the effect of three different mid-meal snacks (i.e. biscuits) on glycaemic response in type 2 diabetes post-surgical patients. Description of intervention: A controlled cross-over study design was followed, whereby all subjects received 3 different treatments on 3 consecutive days at morning and afternoon tea, approximately 10 am and 2 pm, respectively. Recruitment commenced May 2018 and concluded December 2018. Post-surgery T2DM patients were asked to consume two biscuits at each morning tea and afternoon tea, in addition to a provided 45g carbohydrate-controlled meal at breakfast, lunch and dinner, for three consecutive days. The rationale for the 45 g quantity of carbohydrates in the main meals was that the hospital did not want to over-restrict patient food choices and it also wanted to be in line with the moderate carbohydrate intake recommended by the Agency for Clinical Innovation (New South Wales, Australia) for hospital patients with diabetes. On the first day, study participants were provided with four lupin biscuits (Skinnybik™ Lupin, Murrumbeena, Victoria, Australia) containing 20% lupin flour (equivalent to 1 tablespoon of lupin flour), on the second day with four wholemeal spelt biscuits (Skinnybik™ Spelt, Murrumbeena, Victoria, Australia) and on the third day with four hospital standard plain sweet biscuits (Arnott’s Marie Biscuits™, NSW, Australia). The lupin biscuit was provided first since it was expected to have the lowest impact on post-prandial glucose levels, therefore, less potential for carry-over effect of raised glucose levels. The pilot study was reviewed and approved by the Human Research Ethics Committee of La Trobe University (approval number HEC17-073), and permission to run the pilot study at Warringal Private Hospital was provided by the Director of Clinical Services. All participants involved provided informed written consent to participate. Continuous glucose monitoring (CGM) devices were fitted to each patient in the evening before commencing the 3-day diet intervention. Participants were instructed to refrain from consuming any extra snacks during the day and to not add sugar to tea or coffee. In order to asses adherence, the Dietitian visited participants at meal and mid-meal times. For the three study days the amount of food and biscuits consumed by study participants in the main and mid-meals was estimated by the Dietitian through visual inspection. The amount of biscuits consumed, and plate wastage was taken into account when calculating the amount of carbohydrate consumed by study participants.