Randomised controlled trial of a web-based low carbohydrate diet intervention for adults with type 2 diabetes: the T2Diet study protocol

INTRODUCTION: Type 2 diabetes (T2D) management frequently involves a multidisciplinary care team. However, standard care for patients with T2D is the central role of the general practice physician, and consists of routine appointments to monitor glycaemic status and overall health. Dietary modification is an essential component of T2D management. Evidence suggests that a low carbohydrate diet (LCD) provides better clinical outcomes for people with T2D compared with other diets. However, providing dietary support in face-to-face settings is challenged by issues of availability and accessibility. Provided in conjunction with standard care, digital interventions can help bridge this gap. The objective of this paper is to describe the protocol of a randomised controlled trial (RCT) of a web-based intervention that will evaluate the effectiveness of standard care plus web-based LCD intervention when compared with standard care only. METHODS AND ANALYSIS: In a two-arm parallel RCT, 100 adults with non-insulin-dependent T2D aged between 40 and 89 years will be randomised to either a theoretically informed 16-week automated web-based LCD intervention plus standard care or standard care only. LCD recommendations emphasise consuming nutrient-dense whole foods and encourage a daily carbohydrate goal of 50–100 g, with an objective of achieving 10% to <26% carbohydrates from total energy intake. Assessments will take place at baseline and 16 weeks. The primary outcome will be haemoglobin A1c. Additional data collected will include dietary intake, self-efficacy, weight and height, anti-diabetes medication and dosages, and diabetes-related comorbidities. Process evaluation will consist of a mixed-methods assessment of website engagement metrics, user experience and participants’ perspectives. ETHICS AND DISSEMINATION: All study procedures have been approved by the Deakin University Human Research Ethics Committee (2020-349). Study findings will be disseminated widely through public, professional and academic presentation and publication. TRIAL REGISTRATION NUMBER: Australian New Zealand Clinical Trials Registry (ACTRN12621000096853).