title: Risk of obesity in male shift workers: A chronophysiological approach.
abstract: Why are some healthy male shift workers (SWers) overweight [body mass index (BMI) >25 and <30] if not obese (BMI >30)? Seven risk factors potentially causing overweight and obesity were evaluated, namely (1) age, (2) physical/sports activity, (3) length of exposure to shift work (SW), (4) speed of shift rotation, (5) tolerance to SW, (6) internal desynchronization of circadian rhythms and (8) night eating (nocturnal nibbling). "New" as well as "old" data, acquired from longitudinal and individual time series of 5-56 days recording span, were reanalyzed. The data were analyzed from a set of field studies of 67 SWers and 53 non-shift workers (non-SWers). To estimate the respective weight of these factors, a multiple regression analysis (MRA) was used among other statistical tools. A similar age-related increase in BMI was validated (with p < 0.001) in both SWers and non-SWers. However, in SWers, desynchronization of rhythms increases the effect of age on BMI. Length of exposure to SW, tolerance to SW and speed of rotation do not seem to play a role as risk factors. Major effects are likely to relate to a sedentary lifestyle (lack of regular physical or sport activities) (MRA with p < 0.01), as well as, presumably, to a nocturnal nibbling of carbohydrates, which mimics the night eating syndrome.
authors.affiliation: a Department of Laboratory Medicine & Pathology , University of Minnesota, HealthPartners Institute for Education and Research , Minneapolis , MN , USA.|b Department of Pathology , Regions Hospital, St. Paul , MN , USA.
authors.forename: Erhard
authors.initials: E
authors.lastname: Haus
authors.affiliation: c Unité de Chronobiologie , Fondation A. de Rothschild , Paris , France.
authors.forename: Alain
authors.initials: A
authors.lastname: Reinberg
authors.affiliation: d Attention, Orientation, and Chronobiology, INSERM ERI27, EA 3917 , Université Caen Basse Normandie , Caen , France.
authors.forename: Benoît
authors.initials: B
authors.lastname: Mauvieux
authors.affiliation: e Psychologie des Ages de la Vie, EA 2114 , Université F. Rabelais , Tours , France.
authors.forename: Nadine
authors.initials: N
authors.lastname: Le Floc'h
authors.affiliation: a Department of Laboratory Medicine & Pathology , University of Minnesota, HealthPartners Institute for Education and Research , Minneapolis , MN , USA.|b Department of Pathology , Regions Hospital, St. Paul , MN , USA.
authors.forename: Linda
authors.initials: L
authors.lastname: Sackett-Lundeen
authors.affiliation: c Unité de Chronobiologie , Fondation A. de Rothschild , Paris , France.
authors.forename: Yvan
authors.initials: Y
authors.lastname: Touitou
mesh_terms: D000328:Adult; D000375:Aging; D015992:Body Mass Index; D002940:Circadian Rhythm; D005247:Feeding Behavior; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity; D000073577:Shift Work Schedule; D014940:Work Schedule Tolerance
keywords: age; body mass index; body temperature; circadian rhythms; desynchronization; eating behavior; shift work; sport exercise/activities