Efficacy of a teaching kitchen program for patients with type 2 diabetes in Japan: protocol for an open-label...

This open-label randomised controlled trial (Teaching Kitchen for Diabetes in Japan [TKD-J] trial) evaluates the effectiveness of a modified Teaching Kitchen program for Japanese patients with type 2 diabetes. Based on the US Teaching Kitchen Multisite Trial, this program integrates hands-on culinary instruction with evidence-based lectures on nutrition, physical activity, sleep and mindfulness, combined with a personalised approach. This is the first prospective study to assess its impact on glycaemic control and clinical, behavioural, quality-of-life outcomes among Japanese patients with type 2 diabetes.

Two hundred adults aged 20-79 years with type 2 diabetes (HbA1c 6.5-8.9%) and either body mass index ≥23 kg/m² or abdominal obesity (waist ≥85 cm for men or ≥90 cm for women) will be recruited from Osaka University Hospital and 16 affiliated medical institutions in Japan. Participants will be randomly assigned in a 1:1 ratio to either an initial-start or a delayed intervention group (starting after a 4-month delay). The 12-month intervention includes a 4-month main program (weekly) and 8-month maintenance program (monthly), followed by a 4-month post-intervention follow-up. Data will be collected at baseline, and at months 0, 4, 8, 12 and 16. In the initial start group, the baseline and month 0 assessments coincide. In the delayed intervention group, month 0 occurs 4 months after baseline, following a control period. The primary outcome is the change in HbA1c levels during the first 4-month period, which corresponds to the randomised controlled trial phase. Secondary outcomes are changes in fasting plasma glucose, glycaemic variability assessed by blinded continuous glucose monitoring, diabetes treatment, anthropometric and metabolic measures, dietary behaviour, physical activity, sleep, quality of life, mindfulness, cooking skills and self-efficacy. In addition, program satisfaction and records collected through web application will also be assessed. Between-group and within-group changes over time will be analysed using mixed-effects linear regression models.

The study has been approved by the Ethics Committee of Osaka University Hospital (approval number: 23179 [T2]). Written informed consent will be obtained from all participants. Findings will be disseminated through peer-reviewed journals, conference presentations and community outreach.

UMIN-CTR (UMIN000052514).