Abstract P130: Patterns of Change in Step Count During the First 12 Months of a Weight Loss Intervention: A Group-based Trajectory Analysis
Introduction: Increased physical activity (PA) along with reduced energy intake are the key components of weight loss treatment. Objective measures of PA are more reliable than self-report and are infrequently used in clinical trials. Pedometers are inexpensive, often imbedded in mobile devices (e.g. smartphones), and provide a good estimate of overall daily PA.
Hypotheses: We hypothesized that groups with different patterns of daily step counts would emerge over the 12-month period.
Methods: We examined the first 12 months of data from the Self Efficacy Lifestyle Focus Trial during which standard behavioral treatment for weight loss was implemented. Participants were given an Omron HJ-720IT pedometer in the third week of the intervention. Pedometer use was recommended as a way to monitor PA goals, but not required. Mean daily step counts were calculated monthly from pedometer data, with days having zero step counts coded as missing. Group-based trajectory modeling was used to identify distinct classes of trajectories of mean daily step counts.
Results: The sample (N=120) was 81.8% female, 73.6% White with mean (±SD) age of 53.9±9.0 years and baseline body mass index of 33.2±3.8 kg/m2. Four trajectory groups were identified: active (≥10000 steps/day; n=14, 11.7%), somewhat active (7500 to 9999 steps/day; n=34, 28.3%), low active (5000 to 7499 steps/day; n=33, 27.5%), and sedentary (<5000 steps/day; n=39, 32.5%). Over 12 months, the active group increased their daily step counts, while the low active and sedentary groups decreased their step counts.
Conclusions: Based on our findings, it appeared that study participation, including pedometer use, had little effect on step counts, except in the group that was already active. This suggests that less active individuals may have difficulty initiating activities that increase steps even when using a pedometer. Increased emphasis on simple strategies to increase step count and PA are needed to change sedentary habits.
Author Disclosures: C.C. Imes: None. Y. Zheng: None. H. Lu: None. D.D. Mendez: None. R.W. Goode: None. M. Mattos: None. Q. Ma: None. R. Sun: None. Y. Yu: None. C.A. Danford: None. S.M. Sereika: None. L.E. Burke: None.
- © 2016 by American Heart Association, Inc.