ity and to skip breakfast ( table 1 ). When we estimated the effects of procrastination, controlling for all these unhealthy habits, the findings remained significant ( online supplementary table 4 ). Discussion In this cross-sectional study, we examined the association of procrastination, a proxy for hyperbolic discounting and self-control, with obesity-related factors among Japanese male employees. The results showed that white-collar workers with high procrastination levels showed positive associations with BMI, adult weight change, AWG10 and MetS; BMI at age 20 years was not different across procrastination categories. Such significant positive relationships were not observed among blue-collar workers, suggesting that working conditions might modify the association of procrastination with obesity-related factors ( table 2 ). Evidence has indicated that self-regulation (ie, procrastination and undesirable time preference) and socioemotional skills at large scale, as well as cognitive skills (ie, IQ score), have a profound impact on an individual’s health. In addition, there is increasing interest in the hypothesis that socioemotional skills and environmental factors during the life course, such as in the family, school, community and workplace, interact to produce health effects. 12 13 Our study evaluating the interactive effects of procrastination and workplace factors is line with this hypothesis. To our knowledge, this is the first study indicating the joint association of time inconsistency and work condition with obesity. Many empirical studies have shown the associations of time inconsistency with obesity-related habits and obesity. 15 16 Our results showed workers with high procrastination tended to engage in less daily physical activity and to skip breakfast ( table 1 ), behaviours that are well-known risk factors of obesity. However, these unhealthy life habits alone could not explain our results. When we estimated the effects of procrastination, control