[Body mass index in shift workers: relation to diet and physical activity]

Many studies investigated adverse effects of rotating shift work, deriving from modifications of circadian rhythms and alimentary behaviours. This may cause the disregulation of glycolipidic metabolism and of insulin secretion, and the development of central obesity. We conducted the present study in order to assess the differences in body mass index (BMI) between day and shift workers, in relation to diet quality and physical activity.

The study included 341 male subjects (165 day workers and 176 shift workers). Body weight, height, BMI, waist and hip circumferences were measured. Physical activity and diet quality were assessed by self-reported questionnaires.

Shift workers had higher BMI than day workers (27.6 +/- 3.9 vs 26.7 +/- 3.6), and this correlation persisted after adjustment for age. The diet quality was better in shift workers and the level of physical activity was similar in the two groups.

The results of this study indicate that shift work is an independent risk factors in the development of overweight and central obesity. In fact, although the diet quality was even better in shift workers, and the level of physical activity was similar between day and shift workers, we found that shift workers had higher BMI.