Background: Randomised controlled trials have shown that total diet replacement (TDR) can lead to remission of type 2 diabetes. In 2019, the English National Health Service (NHS) committed to establishing a TDR-based interventional programme delivered at scale within real-world environments; development followed of the NHS Type 2 Diabetes Path to Remission (T2DR) programme, a 12-month behavioural intervention to support weight loss involving an initial 3-month period of TDR. We assessed remission of type 2 diabetes for programme participants.

Methods: In this national prospective service evaluation of programme implementation, people in England aged 18-65 years and diagnosed with type 2 diabetes in the last 6 years were referred to the programme between programme launch on Sept 1, 2020, and Dec 31, 2022. Programme data were linked to the National Diabetes Audit to ascertain HbA_1c measurements and glucose-lowering medication prescriptions. The primary outcome was remission of type 2 diabetes at 1 year, defined as two HbA_1c measurements of less than 48 mmol/mol recorded at least 3 months apart with no glucose-lowering medications prescribed from 3 months before the first HbA_1c measurement, and the second HbA_1c measurement recorded 11-15 months after the programme start date. Outcomes were assessed in two ways: for all participants who started TDR on the 12-month programme before January, 2022, for whom there were no missing data; and for all participants who started TDR on the 12-month programme before January, 2022, and had completed the programme (ie, had a valid weight recorded at month 12) by Dec 31, 2022, for whom there were no missing data.

Findings: Between Sept 1, 2020, and Dec 31, 2022, 7540 people were referred to the programme; of those, 1740 started TDR before January, 2022, and therefore had a full 12-month opportunity to undertake the programme by the time of data extraction at the end of December, 2022. Of those who started TDR before January, 2022, 960 (55%) completed the programme (defined as having a weight recorded at 12 months). The mean weight loss for the 1710 participants who started the programme before January, 2022 and had no missing data was 8·3% (95% CI 7·9-8·6) or 9·4 kg (8·9-9·8), and the mean weight loss for the 945 participants who completed the programme and had no missing data was 9·3% (8·8-9·8) or 10·3 kg (9·7-10·9). For the subgroup of 710 (42%) of 1710 participants who started the programme before January, 2022, and also had two HbA_1c measurements recorded, 190 (27%) had remission, with mean weight loss of 13·4% (12·3-14·5) or 14·8 kg (13·4-16·3). Of the 945 participants who completed the programme, 450 (48%) had two HbA_1c measurements recorded; of these, 145 (32%) had remission, with mean weight loss of 14·4% (13·2-15·5) or 15·9 kg (14·3-17·4).

Interpretation: Findings from the NHS T2DR programme show that remission of type 2 diabetes is possible outside of research settings, through at-scale service delivery. However, the rate of remission achieved is lower and the ascertainment of data is more limited with implementation in the real world than in randomised controlled trial settings.

Funding: None.