The Transform Type 2 Diabetes Study

The aim of this mixed-methods, 12-month interventional study is to understand the effectiveness and acceptability of dietary interventions in type 2 diabetes mellitus (T2DM) in an ethnically diverse population. Three dietary interventions will be offered (total diet replacement, intermittent fasting and a low-carbohydrate diet) and two modes of remote care delivery will be used (group and one-to-one).

To date, there is little evidence focusing on preferences, motivating factors, and engagement in adults with type 2 diabetes when following dietary interventions to improve glycaemic control, nor on patient responses to remote group and one-to-one programs. In particular, this evidence is not available in populations with high levels of deprivation and that are culturally and ethnically diverse in which diabetes is most prevalent.

The 120 participants will be recruited from GP practices in the Southwark area. Practices will be split into two comparable groups based on the demographic and clinical data of eligible patients. Participants from one group of practices will be offered a one-to-one lifestyle coaching program. Patients from the other group of practices will be offered a group lifestyle coaching program. The aim is to recruit 60 patients for each arm.

All participants will be offered a choice of three dietary approaches: total diet replacement (TDR), intermittent fasting 5:2 approach and a low-carbohydrate diet. Interventions will be led by Diabetes Specialist Dietitians (DSD) and all participants will have access to supporting learning materials. All care will be delivered remotely.

Participants will receive intensive support in the first 16 weeks and follow-up support for a further 36 weeks. Participants on the one-to-one pathway will access their support via the Oviva app, telephone or video calls. Participants allocated to the group intervention will access their support through video group sessions hosted by their DSD, and will be offered the opportunity to use a secure group chat for patients, between sessions.

The evaluation will use a mixed methods approach, combining qualitative and quantitative analysis. Surveys, interviews, written material, and quantitative data will be used. This will allow for establishing learnings regarding patient choice, preference, experience, motivation, and engagement. Gaining insight into these perceptions can support our understanding as to how to best support engagement, understand the suitability of dietary interventions for different patients, and improve the quality and delivery of lifestyle interventions to support patients with type 2 diabetes in the future.

Eligibility Criteria:
Inclusion Criteria:

* Registered with one of the Nexus Group GP Practices
* Willing to give consent for participation including collection of clinical outcomes
* Diagnosis of type 2 diabetes
* Minimum age of 18 years
* Maximum age of 70 years
* Minimum BMI of 27kg/m² (adjusted to 25kg/m² in people of South Asian or Chinese origin)
* Upper weight limit of 180kg (due to upper weight limit of BodyTrace scales)
* HbA1c eligibility:
* If on diabetes medication, HbA1c ≥ 43 mmol/mol
* If on diet alone, HbA1c ≥ 48 mmol/mol
* HbA1c \<108mml/mol
* Ability to speak, read and receive care in English
* Access to internet and email address

Exclusion Criteria:

* Currently taking insulin
* Pregnant or planning to be pregnant in the next 6 months
* Current breastfeeding
* Significant physical comorbidities:
* Active cancer, receiving treatment
* Myocardial infarction or stroke in last 6 months
* Severe heart failure defined as equivalent to the New York heart Association grade 3 or 4 (NYHA)
* eGFR \<30 mls/min/1.73m2
* Active liver disease (except non-alcoholic fatty liver disease (NAFLD),Severe angina, cardiac arrhythmia including atrial fibrillation or prolonged QT syndrome
* Active substance use disorder
* Active eating disorder
* Porphyria
* On current weight management programme / had or awaiting bariatric surgery (unless willing to come off waiting list)
* Health professional assessment that the person is unable to understand or meet the demands of the programme and/or monitoring requirements
* Taking monoamine-oxidase inhibitor medication
* Taking warfarin
* Taking varenicline (smoking cessation medication)
* Have attended for monitoring and diabetes review when this was last offered, including retinal screening, and commit to continue attending reviews, even if remission is achieved
* Active/investigation for gastric or duodenal ulcers