Effect of Daily Self-weighing on Weight Loss in Adults

Limited experimental evidence has examined the impact of daily self-weighing on weight loss and psychological outcomes. The purpose of this dissertation was to assess the effect of daily self-weighing on weight loss, behavioral, and psychological outcomes among overweight and obese adults using an experimental design and robust analytic methods. This dissertation followed three aims. Aim 1 consisted of a secondary data analysis among participants enrolled in a 12-month Internet-based weight loss intervention to examine the association between daily weighing and weight loss and explore whether diet and physical activity behaviors explain that relationship. Those who reported daily weighing had greater percent weight loss compared to those who reported less frequent weighing at 6 months [(8.27% (5.40) vs. 5.51% (5.41); p=.003] and 12 months [8.09% (7.81) vs. 4.60% (6.35); p=.004]. At 6 months, multiple mediation analysis showed that eating and exercise behaviors acted as mediators between daily self-weighing and weight loss. At 12 months, only eating behaviors explained the relationship. Aim 2 included a randomized controlled trial (n=91) comparing a 6-month low-intensity, daily self-weighing intervention to a delayed intervention control group that included an objective measure of self-weighing. On average, the intervention group self-weighed more days per week (6.1±1.1 vs. 1.1±1.5; p<.0001) and lost significantly more weight compared to the control group [Mean (95%CI); 3 months: -4.41%(-5.5, -3.3) iv vs. -0.37%(-1.5, .76); 6 months: -6.55%(-7.7, -5.4) vs. -0.35%(-1.5, .79); group x time interaction: p<.001]. At 6 months, a greater percentage of the intervention group achieved 5% (42.6% vs. 6.8%; p<.0001) and 10% weight loss (27.7% vs. 0%; p<.0001). Aim 3 examined the psychological effects of the daily self-weighing intervention compared to controls. There were no significant differences between groups in depressive symptoms, anorectic cognitions, disinhibition, susceptibility to hunger, and binge eating. At 6 months, there was a significant group by time interaction for both body dissatisfaction (p=.007) and dietary restraint (p<.001) with the intervention group reporting improved outcomes on these constructs. The results of this dissertation indicate that daily self-weighing is a feasible and effective behavior for weight loss among overweight and obese adults that does not lead to adverse psychological outcomes.Doctor of Philosoph