Analysing self-regulatory behaviours in response to daily weighing: a think-aloud study with follow-up interviews.

To examine the extent to which people who are trying to lose weight naturally self-regulate in response to self-weighing and to identify barriers to self-regulation. Twenty-four participants, who were overweight and trying to lose weight, recorded their thoughts during daily weighing for eight weeks. Semi-structured follow-up interviews assessed participant experiences. Qualitative analysis identified steps of the self-regulation process and barriers to self-regulation. Exploratory regression analysis assessed the relationship between the self-regulation steps and weight loss. On 90% of 498 occasions, participants compared their weight measurement to an expectation or goal, and on 58% they reflected on previous behaviour. Action planning only occurred on 20% of occasions, and specific action planning was rare (6%). Only specific action planning significantly predicted weight loss (-2.1 kg per 1 SD increase in the predictor, 95% CI = -3.9, -0.3). Thematic analysis revealed that barriers to the interpretation of daily weight changes were difficulties in understanding day-to-day fluctuations, losing the overview of trends, forgetting to weigh, and forgetting previous measurements. Specific action planning can lead to weight loss, but is rare in a naturalistic setting. Barriers to self-regulation relate to the interpretation of weight changes.