Physical Activity Self-Monitoring and Weight Loss

• DOI: 10.1249/mss.0b013e31820b9395
• Publication Date: 2010-12-31T17:25:49Z
• Authors: MOLLY B. CONROY; KYEONGRA YANG; OKAN U. ELCI; KELLEY PETTEE GAB...; MINDI A. STYN; JING WANG; ANDREA M. KRISKA; SUSAN M. SEREIKA; LORA E. BURKE
• Keywords: Adult; Male; Feeding Behavior; Middle Aged; Motor Activity; Overweight; Body Mass Index; Diagnostic Self Evaluation; 03 medical and health sciences; 0302 clinical medicine; Surveys and Questionnaires; Weight Loss; Humans; Patient Compliance; Female; Monitoring, Physiologic

Weight loss has been associated with higher physical activity (PA) levels and frequent dietary self-monitoring. Less is known about how PA self-monitoring affects adherence to PA goals, PA levels, and weight change.The SMART Trial is a clinical weight loss trial in which 210 overweight adults were randomized equally to one of three arms: 1) paper record (PR), 2) personal digital assistant with self-monitoring software (PDA), and 3) PDA with daily tailored feedback message (PDA + FB). PA self-monitoring and adherence to PA goals were based on entries in weekly submitted diaries. PA levels were measured via self-report by the past 6-month Modifiable Activity Questionnaire at baseline and 6 months.Data are presented on 189 participants with complete 6-month PA data (84% female, 77% white, mean age = 47.3 ± 8.8 yr, mean body mass index = 34.1 ± 4.5 kg·m(-2)). Median PA level was 7.96 MET·h·wk(-1) at baseline and 13.4 MET·h·wk(-1) at 6 months, with significant PA increases in all three arms. PDA + FB arm had a higher mean number of weekly self-monitoring entries than the PR arm (3.4 vs 2.4, P = 0.003) and were more likely to maintain high (i.e., 100%) adherence to PA goals over time than the PDA (P = 0.02) or PR arms (P = 0.0003). Both PA self-monitoring and adherence to PA goals were related to higher PA levels at 6 months. A higher mean rate of PA self-monitoring was associated with a greater percentage of weight decrease (ρ = -0.49, P < 0.0001) at 6 months.PA self-monitoring and adherence to PA goals were more likely in participants in the PDA + FB arm and in turn predicted higher PA levels and weight loss.