title: The joint influence of gender and amount of smoking on weight gain one year after smoking cessation.
abstract: Weight gain is often associated with smoking cessation and may discourage smokers from quitting. This study estimated the weight gained one year after smoking cessation and examined the risk factors associated with weight gain in order to identify socio-demographic groups at higher risk of increased weight after quitting. We analyzed data from 750 adults in two randomized controlled studies that included smokers motivated to quit and found a gradient in weight gain according to the actual duration of abstinence during follow-up. Subjects who were abstinent for at least 40 weeks gained 4.6 kg (SD = 3.8) on average, compared to 1.2 kg (SD = 2.6) for those who were abstinent less than 20 weeks during the 1-year follow-up. Considering the duration of abstinence as an exposure variable, we found an age effect and a significant interaction between sex and the amount of smoking before quitting: younger subjects gained more weight than older subjects; among light smokers, men gained more weight on average than women one year after quitting, while the opposite was observed among heavy smokers. Young women smoking heavily at baseline had the highest risk of weight gain after quitting.
authors.affiliation: Department of Ambulatory Care and Community Medicine, University of Lausanne, Rue du Bugnon 44, CH-1011 Lausanne, Switzerland. isabella.locatelli@chuv.ch.
authors.forename: Isabella
authors.initials: I
authors.lastname: Locatelli
authors.affiliation: Department of Ambulatory Care and Community Medicine, University of Lausanne, Rue du Bugnon 44, CH-1011 Lausanne, Switzerland. tinh-hai.collet@chuv.ch.
authors.forename: Tinh-Hai
authors.initials: TH
authors.lastname: Collet
authors.affiliation: Department of Ambulatory Care and Community Medicine, University of Lausanne, Rue du Bugnon 44, CH-1011 Lausanne, Switzerland. carole.clair@hospvd.ch.
authors.forename: Carole
authors.initials: C
authors.lastname: Clair
authors.affiliation: Department of General Internal Medicine, Inselspital, Bern University Hospital, CH-3010 Bern, Switzerland. nicolas.rodondi@insel.ch.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Rodondi
authors.affiliation: Department of Ambulatory Care and Community Medicine, University of Lausanne, Rue du Bugnon 44, CH-1011 Lausanne, Switzerland. jacques.cornuz@chuv.ch.
authors.forename: Jacques
authors.initials: J
authors.lastname: Cornuz
mesh_terms: D000328:Adult; D015331:Cohort Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking / Q000453:epidemiology; D016540:Smoking Cessation; D013997:Time Factors; D014026:Nicotiana / Q000737:chemistry*; D015430:Weight Gain