To determine the effectiveness of a personal support lifestyle education programme (PSMetS) for reducing risk factors in individuals with metabolic syndrome (MetS).

A two-arm randomised controlled trial.

Companies in metropolitan Tokyo, Japan.

Male workers with diagnosed MetS or a high risk for MetS according to the Counselling Guidance Program, Japan (n 193).

The reduction in the number of risk factors for MetS (as defined according to the criteria published by the Japanese Ministry of Health, Labor and Welfare in April 2007 (MHLW-MetS)) in the PSMetS group was not significantly different from that in the usual care group by van Elteren’s test (baseline-adjusted P=0·075) for intention-to-treat (ITT), while it was significant (baseline-adjusted P=0·038) for per-protocol set (PPS). The proportion of MHLW-MetS was significantly different between groups by van Elteren’s test (baseline-adjusted P=0·031). Two components of MHLW-MetS showed significant reductions in the PSMetS group: waist circumference (baseline-adjusted P=0·001) and BMI (baseline-adjusted P=0·002). PPS and ITT analyses showed similar results.

For male workers with MHLW-MetS or a high risk of MHLW-MetS, PSMetS reduced the number of risk factors for MHLW-MetS.