['It is well known that body weight loss through a direct (supervised) lifestyle intervention (LSI) improves obesity-related metabolic disorders. The purpose of this study was to investigate the effects of an indirect LSI on weight loss and metabolic syndrome (MetS) in spouses of LSI participants.', 'A total of 104 men (abdominal circumference > or = 85 cm; age, 52.1 + or - 9.3 years) were assigned to one of three groups: no intervention (NI, n = 34), direct intervention (DI, n = 34) or indirect intervention (II, n = 36), the last of which consisted of subjects who did not participate in the direct LSI but whose wives did. Body weight and MetS components were measured before and after a 14-week intervention. Daily energy intake and activity-related energy expenditure were assessed before and during the intervention. The LSI program was mainly consisted of dietary modifications with a physical activity program.', 'No differences were observed across the three groups in any of the measures at baseline. Significant differences were observed among the groups in weight loss (NI, -0.7 + or - 1.4; DI, -6.2 + or - 3.3 and II, -4.4 + or - 3.7 kg) during the intervention. Along with the body weight reductions, significant improvements were observed in most of MetS components within the DI and II groups. When analyzing the spouse pairs in group II, significant correlations were observed in weight loss (r = 0.57) and decreased total energy intake (r = 0.54) between wives and husbands.'] Does indirect lifestyle intervention through wives improve metabolic syndrome components in men?