Food is Medicine: an Australian trial of a medically tailored meals intervention on type 2 diabetes and heart disease outcomes in adults

Over 26 weeks, each intervention participant will receive 20 pre-prepared meals a fortnight (i.e. lunch and dinner each day for 5 days per week) and a bag of mixed nuts (approximately 300g to provide 10 serves per fortnight). Meals will be purchased from three existing home-meal delivery companies, which have been screened to meet current evidence-based nutritional recommendations for people with type 2 diabetes. Meals will typically contain on average 1500kJ per meal, with 37% carbohydrate, 33% fat and 30% protein. Different sets of meals will be available to enable flexibility and cater to dietary preferences, and participants will be provided with a booklet of the meal set options to choose from. Participants will receive the same meal set until they request for a different meal set. Individual meals will come with specific information about recommended storage, preparation, and heating instructions. Intervention participants will also receive 3 consults (up to 30 minutes) with dietitians at week 2, 4 and 8, to encourage uptake of meals and improvements in diet quality overall. Participants will also receive a $50 voucher each at baseline and week 13 and a $150 voucher at week 26 (after completion of pathology data collection). Intervention participants that are on insulin or other glucose lowering medication will be advised to check their blood sugar levels premeal when commencing the provided meals to ensure safety, or as otherwise specifically advised by their treating physician. Any changes to diabetes medication requirements will be at the discretion of their treating clinician and documented. All participants will also be advised to follow up with their own doctors closely throughout the study, and that they should contact their treating doctors if they experience hypoglycaemia (self-monitored blood glucose <3mmol/L) or hypoglycaemic symptoms. A hot line for the participants to call an accredited diabetes educator will also be made available to answer any urgent questions. To monitor adherence to the intervention study staff who conduct the diet consultations will log the number of dietary counselling sessions with each participant and collect the responses to three routine questions related to meal acceptability and uptake at week 2, 4 and 8. Participants will also be asked to complete a self-administered Process Evaluation questionnaire at week 13 and week 26 of the intervention which includes questions about average number of meals consumed each week. At end of the study, key informant interviews (up to 45 minutes in duration) will be conducted by phone (i.e. Microsoft Teams or Zoom audio function) with one to two purposively selected representatives each from the food supplier (Managing Directors/Chief Executive Officers and other staff engaged in the intervention), clinical staff, and study staff as well as 35 purposively selected intervention participants (with a range of characteristics). For current participants of the study, they will be asked by study staff at their final visit if they are interested in partaking in the interview (they have already indicated their consent to the interview as part of the broader trial consent). We will initially select 4 participants to take part in these interviews and then seek maximum variability sampling (in terms of age, sex, severity of diabetes based on their baseline HbA1c, and income) to recruit additional participants with the goal of achieving thematic saturation. We anticipate 35 participants will be involved in the qualitative data collection. For the meal supplier interviews, study staff are in contact with them as part of running the study and will ask who may be willing to be interviewed. For clinicians, relationships exist (some are collaborators on this study) and these contact details will be used to ask who may be willing to be interviewed and provide the Information Statement to them. For study staff, willing interviewees will self-nominate and access the Information Statement and use our usual means of contacting each other. The interviews will seek to obtain an in-depth understanding of what worked (or not), for whom and how, challenges and facilitators, and any adaptations throughout the implementation process. For all key informant interviews (except among trial participants), verbal consent will be obtained at the start of the interviews as per the verbal consent script and consent will be audio-recorded.