The primary objective of this non-experimental, cross-sectional study was to examine the differences based on obesity-related health risk (National Institute of Health [NIH], 1998) in terms of physical activity, sedentary behaviour, and well-being in adults. Participants (N = 50; Mage = 38.50, SDage = 14.21) were asked to wear a SenseWear Armband (SWA; BodyMedia, Inc., Pittsburgh, PA) across a seven day monitoring period followed by a questionnaire package. Physical activity measures used consisted of time spent in active energy expenditure (i.e., ≥ 3.0 metabolic equivalent units) in bouts of ten minutes or more (AEE-10; CSEP, 2013) and the number of steps taken per day. Sedentary behaviour was classified as any ambulatory activity < 1.5 metabolic equivalent units (Sedentary Behaviour Research Network, 2012). The Activation Deactivation Adjective Checklist (AD ACL; Thayer, 1989) served as the measure of affect. Using NIH (1998) criteria, participants were classified as either least (n = 16), increased (n = 21), or high (n = 13) for obesity-related health risk based on waist circumference and Body Mass Index scores. Based on study results, significant differences were found in individual’s activity behaviour based on their obesity-related health risk classification (p < .05; ηp2 = .20). Through examining each dependent variable separately, significant differences were only found in the amount of time spent in AEE-10 (p = .002; η2 = .12). More specifically, those who were at least risk for obesity-related health complications participated in more AEE-10 than those classified as high risk (p < .05). Differences (p > .05; ηp2 = .18) across the three obesity-related health risks were not found for AD ACL scores. Therefore, based on the present investigation, attention should be placed on the promotion of engaging in more ten minute bouts in an effort to reduce obesity-related complications; specifically for those at high risk.