Relationship between rice consumption and body weight gain in Japanese workers: white versus brown rice/multigrain rice.

Increasing obesity rates have driven research into dietary support for body weight control, but previous studies have only assessed changes in body weight of ±3 kg. We investigated the relationships between white or brown/multi-grain rice consumption and 1-year body weight gain ≥3 kg in Japanese factory workers (n = 437). Routine medical check-up data from a 1-year nutrition and lifestyle cohort study were analysed. Participants were divided into white rice and brown/multi-grain rice consumption groups and further classified by tertile of rice consumption. Multiple logistic regression analyses were performed by tertile. At 1 year, high white rice consumption was significantly associated with increased risk of body weight gain ≥3 kg compared with low white rice consumption, maintained after adjustment for age, sex, and consumption of other obesogenic foods (p = 0.034). In the brown/multi-grain rice consumption group, however, there was no significant difference in risk between high and low consumption, even after multi-variate adjustment (p = 0.387). The consumption of white rice, but not brown rice/multi-grain rice, was positively correlated with the risk of a 1-year body weight gain of 3 kg or more. This suggests that brown rice/multi-grain rice consumption is useful for body weight control among Japanese workers.