Regular self-monitoring of body weight is an effective intervention in weight loss programmes and, especially, in weight maintenanc. Frequent self-monitoring is assumed to improve self-awareness, provide early detection of subtle weight increases and prevent weight regain after weight loss. Regular self-weighing is recommended as part of the behavioural therapy for weight management by the National Institute of Health and is deemed ‘crucial’ for long-term weight maintenance. Frequent self-monitoring may also promote weight management during the holiday season when the risk of weight gain is high.

Van Wormer et al. reviewed 12 studies that used self-weighing as an intervention for weight loss and weight maintenance. In 11 of the studies, more frequent self-weighing was associated with greater weight loss or weight gain prevention: weekly and daily self-weighers held a 1-3 BMI unit advantage compared with individuals who did not weigh themselves as frequently. For a 1.7 m-tall person this means a 3-9 kg lower weight. In the study by Linde et al., daily self-weighing was associated with the greatest weight loss outcomes compared with self-weighing on a weekly, monthly or semi-monthly basis, or never. Van Wormer et al. used self-weighing frequency to predict a weight change over two years; more frequent self-weighing was associated with slower weight (re)gain and, for obese individuals, also possibly weight loss. Fujimoto et al. found that subjects who were instructed to weigh themselves as frequently as four times a day and draw a graph of their weight lost twice as much weight as the group that only had behaviour therapy. In a 20-week study by Gokee-LaRose et al., one group was instructed to obtain daily weights with a digital memory scale whereas the other group was instructed not to weight themselves until week 11 and then to obtain weekly weights. Both groups received behavioural therapy. There was no significant difference in weight loss between the groups, but weighing frequency and weight loss were associated. Though it seems that frequent self-weighing is advantageous, the optimal self-weighing frequency is not known.

Studies that investigate the effect of self-weighing frequency on weight control do not usually analyse self-weighing data, but evaluation is often based on a retrospectively self-reported monitoring frequency. Participants are typically asked to summarize their long-term self-weighing as being on a daily, weekly or monthly basis. However, categorized response options may not reflect true weighing behaviour over time, added to the fact that the self-weighing frequency may vary greatly over time. Both Van Wormer et al. [10] and Gokee-LaRose et al. studied the actual self-weighing frequency using a weight scale that automatically transmitted or saved weight information to counsellors. An association between frequent self-weighing and greater weight loss was found in both studies. However, in these studies, the self-weighing information was reduced to a single frequency value that does not reflect temporal variations in self-weighing activity.