Intermittent Versus Continuous Low-Energy Diet in Patients With Type 2 Diabetes: Protocol for a Pilot Randomized Controlled Trial

Do people with type 2 diabetes find continuous and intermittent low-energy diets for weight loss and diabetes remission acceptable?

BACKGROUND

The Manchester Intermittent versus Daily Diet App Study (MIDDAS) tested the feasibility and potential efficacy of two remotely delivered low-energy diet (LED) programmes (800 kcal/day) to support weight loss and remission of type 2 diabetes: continuous [CLED] (8 weeks of daily LED) and intermittent [ILED] (2 days of LED/week for 28 weeks). Understanding participant experiences can help us to understand the acceptability of LED programmes to people with type 2 diabetes, informing future programme development and implementation.

METHODS

Twenty participants (10 CLED; 10 ILED) took part in interviews conducted at the end of the active weight loss phase (CLED week 12, ILED week 28). Interviews were transcribed and analysed thematically using the template analysis approach, with an a priori focus on acceptability. Four themes are presented: prospective acceptability, intervention coherence and perceived effectiveness, opportunity costs and self-efficacy.

RESULTS

Both remotely supported CLED and ILED interventions appeared acceptable to participants. CLED participants found the rapid initial weight loss phase comparatively easy and highly motivating but expressed more concerns around weight maintenance. ILED participants found the more gradual weight loss initially frustrating but expressed greater confidence in their longer-term adherence. The importance of continued individualised support from healthcare professionals was emphasised, and evidence of weight loss and improvement in other medical markers through monitoring via the mobile phone app was useful.

CONCLUSION

Different approaches to remotely delivered LEDs appear acceptable; therefore asking patients which approach may be more acceptable to them may be a useful way to offer individualised and tailored support.

Manchester Intermittent versus Daily Diet App Study (MIDDAS): A pilot randomized controlled trial in patients with type 2 diabetes

AIMS

To test the feasibility and potential efficacy of remotely supported intermittent low-energy diets (ILEDs) and continuous low-energy diets (CLEDs) in people with type 2 diabetes (T2D) and the feasibility of a randomized controlled trial comparing the two approaches.

MATERIALS AND METHODS

Seventy-nine adults with overweight/obesity and T2D (≤8 years duration) were randomized 1:1 to CLED (8 weeks/56 days of daily Optifast 820 kcal (3430 kJ) diet) or isoenergetic ILED (2 days of Optifast and 5 days of a Mediterranean diet/week for 28 weeks). Weight maintenance/continued weight loss was undertaken for the remainder of the 52 weeks. Both groups received frequent telephone or the Oviva app support. Feasibility outcomes included study uptake, retention, app usage, dietary adherence, weight loss and change in glycated haemoglobin (HbA1c) at 52 weeks.

RESULTS

We enrolled 39 ILED and 40 CLED participants and 27 (69%) ILED and 30 CLED (75%) attended the 52-week follow-up. Eighty-nine per cent (70 of 79) started using the app and 86% (44 of 51) still used the app at 52 weeks. Intention-to-treat analysis at 52 weeks showed percentage weight loss was mean (95% confidence interval) -5.4% (-7.6, -3.1%) for ILED and -6.0% (-7.9, -4.0%) for CLED. HbA1c <48 mmol/mol was achieved in 42% of both groups. Mean (95% confidence interval) changes in the T2D medication effect score were 0.0008 (-0.3, 0.3) for ILED and -0.5 (-0.8, -0.3) for CLED.

CONCLUSION

The study shows the feasibility and potential efficacy of remotely delivered ILED and CLED programmes for weight loss and HbA1c reduction, and the feasibility of a randomized controlled trial comparing the two approaches.