Associations between obesity and socio-demographic and behavioral characteristics varybetween populations. Exploring such differences should throw light on factors related to obesity. Weexamined associations between general obesity (GO, defined by body mass index) and abdominalobesity (AO, defined by waist-to-hip ratio) and sex, age, socio-economic characteristics (education,financial situation, marital status), smoking and alcohol consumption in women and men aged40–69 yearsfrom the Know Your Heart study (KYH, Russia,N= 4121, 2015–2018) and the seventhTromsø Study (Tromsø7, Norway,N= 17,646, 2015–2016). Age-standardized prevalence of GO andAO was higher in KYH compared to Tromsø7 women (36.7 vs. 22.0% and 44.2 vs. 18.4%, respectively)and similar among men (26.0 vs. 25.7% and 74.8 vs. 72.2%, respectively). The positive associationof age with GO and AO was stronger in KYH vs. Tromsø7 women and for AO it was stronger inmen in Tromsø7 vs. KYH. Associations between GO and socio-economic characteristics were similarin KYH and Tromsø7, except for a stronger association with living with spouse/partner in KYHmen. Smoking had a positive association with AO in men in Tromsø7 and in women in both studies.Frequent drinking was negatively associated with GO and AO in Tromsø7 participants and positivelyassociated with GO in KYH men. We found similar obesity prevalence in Russian and Norwegianmen but higher obesity prevalence in Russian compared to Norwegian women. Other results suggestthat the stronger association of obesity with age in Russian women is the major driver of the higherobesity prevalence among them compared to women in Norway. CC BY 4.0Correspondence: kamila.k.kholmatova@uit.noFunding: The KYH study was part of the International Project on Cardiovascular Disease in Russia (IPCDR). It was funded by the Wellcome Trust Strategic Award (100217), by funds from UiT The Arctic University of Norway; Norwegian Institute of Public Health; the Norwegian Ministry of Health and Social Affairs. Tromsø7 was funded by UiT The Arctic University of Norway, Northern Norway Regional Health Authority, Norwegian Ministry of Health and Social Services, and Troms County. Contribution of Sofia Malyutina was supported by the Russian Academy of Science, State target (#122031700094).