Impact of social support intensity on walking in the severely obese: a randomized clinical trial

Objective: There are few established methods for promoting physical activity (PA) in the severely obese. Because social support is a potential method for promoting PA, we compared mean steps/day during 18 weeks in severely obese outpatients receiving either standard support (SS) or added support (AS). Methods and Procedures: Eighty severely obese outpatients from an obesity clinic were invited; 66 provided written consent, 55 were randomized, and 42 were included in final analyses (9 men, 33 women; age 44.4 ± 13.1 years; BMI 41.9 ± 5.5 kg/m²). All participants received a pedometer and a walking promotion booklet. In addition to SS, the AS group received ten 2‐h group counseling sessions aimed at increasing weekly accumulated steps, every second week during the study. Each participant was asked to complete a 7‐day walking diary every second week (10 observations). Results: Baseline steps/day was 6,912 for the AS group and 5,311 for the SS group (P = 0.023). Data at 18 weeks showed that the AS group recorded 10,136 steps/day and the SS group 6,118 steps/day (P = 0.024). There was no allocation × time interaction (P = 0.46). During the follow‐up period as a whole, the AS group recorded 1,794 more steps/day than the SS group (P = 0.0074). Discussion: The AS group recorded more steps/day than the SS group, reaching a mean level of ～10,000 steps/day. However, the nonsignificant interaction between allocation × time suggests that this difference was present already at baseline and did not increase during follow‐up.