Sitting time and obesity in a sample of adults from Europe and the USA

Abstract

Background: Obesity is a risk factor for many chronic diseases and the prevalence is increasing worldwide. Research suggests that sedentary behaviour (sitting) may be related to obesity.

Aim: To examine the association between sitting time and obesity, while controlling for physical activity, in a large international sample.

Subjects and methods: In total, 5338 adults from the UK, USA, Germany, Spain, Italy, France, Portugal, Austria and Switzerland self-reported their total daily sitting time, physical activity, age, height and weight. BMI (kg/m²), total physical activity (MET-minutes/week) and sitting time (hours/day) were derived. Participants were grouped into quartiles based on their daily sitting time (<4, 4-≤6, 6-≤8 and >8 hours/day) and logistic regression models explored the odds of being obese vs normal weight for each sitting time quartile.

Results: Participants in the highest sitting time quartile (≥8 hours/day) had 62% higher odds of obesity compared to participants in the lowest quartile (<4 hours/day) after adjustment for physical activity and other confounding variables (OR = 1.62, 95% CI = 1.24-2.12, p < .01).

Conclusion: Sitting time is associated with obesity in adults, independent of physical activity. Future research should clarify this association using objective measures of sitting time and physical activity to further inform health guidelines.

Keywords: Body mass index; International Physical Activity Questionnaire; sedentary behaviour.