JMIR Publications

ABSTRACT

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:

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 one year. Longitudinal weight measurement data of the users was 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 9,768 participants (67% men; age 41.5 years; BMI 26.8 kg/m2). Of them, 4,003 (41.0%), 3,748 (38.4%) and 2,017 (20.7%) were normal-weight, overweight and obese, respectively. During the mean follow-up time of 1,085 days, the mean weight change was -0.59 kg (-0.37 %), and the mean number of self-weighs per week was 2.8. The self-weighing frequency correlated inversely with weight change, r=-0.118 (P < 0.001). Among normal-weight, overweight and obese individuals, the correlations were r= -0.100 (P < 0.001), r= -0.123 (P < 0.001), and r= -0.157 (P < 0.001), respectively. Of all participants, 72.53% had at least one period of 30 days or longer without weight measurements. During the break, the weight increased, and the 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 < 0.001).

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 benefits of regular self-weighing were more pronounced for overweight or obese individuals.