%0 Journal Article
%@ 1438-8871
%I JMIR Publications
%V 23
%N 6
%P e25529
%T Frequency of Self-Weighing and Weight Change: Cohort Study With 10,000 Smart Scale Users
%A Vuorinen,Anna-Leena
%A Helander,Elina
%A Pietilä,Julia
%A Korhonen,Ilkka
%+ VTT Technical Research Centre of Finland, P.O. Box 1300, Tampere, FI-33101, Finland, 358 408485966, anna-leena.vuorinen@vtt.fi
%K self-monitoring
%K self-weighing
%K weight change, weight loss, normal weight, overweight, obese, temporal weight change
%D 2021
%7 28.6.2021
%9 Original Paper
%J J Med Internet Res
%G English
%X Background: Frequent self-weighing is associated with successful weight loss and weight maintenance during and after weight loss interventions. Less is known about self-weighing behaviors and associated weight change in free-living settings. Objective: This study aimed to investigate the association between the frequency of self-weighing and changes in body weight in a large international cohort of smart scale users. Methods: This was an observational cohort study with 10,000 randomly selected smart scale users who had used the scale for at least 1 year. Longitudinal weight measurement data were analyzed. The association between the frequency of self-weighing and weight change over the follow-up was investigated among normal weight, overweight, and obese users using Pearson’s correlation coefficient and linear models. The association between the frequency of self-weighing and temporal weight change was analyzed using linear mixed effects models. Results: The eligible sample consisted of 9768 participants (6515/9768, 66.7% men; mean age 41.5 years; mean BMI 26.8 kg/m2). Of the participants, 4003 (4003/9768, 41.0%), 3748 (3748/9768, 38.4%), and 2017 (2017/9768, 20.6%) were normal weight, overweight, and obese, respectively. During the mean follow-up time of 1085 days, the mean weight change was –0.59 kg, and the mean percentage of days with a self-weigh was 39.98%, which equals 2.8 self-weighs per week. The percentage of self-weighing days correlated inversely with weight change, r=–0.111 (P<.001). Among normal weight, overweight, and obese individuals, the correlations were r=–0.100 (P<.001), r=–0.125 (P<.001), and r=–0.148 (P<.001), respectively. Of all participants, 72.5% (7085/9768) had at least one period of ≥30 days without weight measurements. During the break, weight increased, and weight gains were more pronounced among overweight and obese individuals: 0.58 kg in the normal weight group, 0.93 kg in the overweight group, and 1.37 kg in the obese group (P<.001). Conclusions: Frequent self-weighing was associated with favorable weight loss outcomes also in an uncontrolled, free-living setting, regardless of specific weight loss interventions. The beneficial associations of regular self-weighing were more pronounced for overweight or obese individuals. 
%M 34075879
%R 10.2196/25529
%U https://www.jmir.org/2021/6/e25529
%U https://doi.org/10.2196/25529
%U http://www.ncbi.nlm.nih.gov/pubmed/34075879