[Weight change following a self-selected, type-tailored lifestyle modification program for employees with suspected...

This single-arm before-after study examined short-term changes in body weight following a 28-day self-selected, type-tailored lifestyle modification program implemented before workplace health checkups. Participants self-identified one of the seven types based on brief descriptions and created a personalized program.

Employees aged 35-64 years from Kao Group corporations who met body mass index (BMI) ≥ 25 kg/m² or waist circumference criteria (men ≥ 85 cm, women ≥ 90 cm) were eligible. Participants self-selected either a "supported" (daily prompts for record entry and weekly automated feedback) or "self-managed" (booklet only) course and followed the 28-day program. The primary outcome was the change in self-measured body weight from pre- to post-program. Secondary outcomes included changes in annual health checkup parameters (body weight, BMI, waist circumference, blood pressure, blood glucose, and lipid profiles), specific health guidance levels, and metabolic syndrome (MetS) classification.

Among 162 analyzed participants (supported: 108, self-managed: 54), the mean change in body weight was -1.75 kg (95% confidence interval [CI], -2.01 to -1.43, p < .001). Mean changes by course were -1.67 kg (supported) and -1.93 kg (self-managed) (both p < .001). The adjusted estimate (controlling for sex, age, and baseline weight) was similar (-1.75 kg, 95% CI; -2.07 to -1.42, p < .001). Waist circumference decreased significantly. The proportion of participants requiring specific health guidance and those classified as having MetS or pre-MetS decreased by approximately 15% and 8%, respectively. No significant changes were observed in blood pressure, blood glucose levels, or lipid profiles.

Short-term decreases in self-measured body weight and waist circumference were observed after the 28-day program, along with decreased proportions requiring health guidance or classified as having MetS or pre-MetS. However, owing to the single-arm design and potential confounding factors, causal attribution to the intervention could not be made. Randomized controlled trials and longer-term follow-up are required to confirm its effectiveness and sustainability.