A Single Motivational Lecture Can Promote Modest Weight Loss: A Randomized Controlled Trial

Background: Obesity is a public health problem worldwide. To widely disseminate weight-loss interventions across the target population, a cost-effective approach is needed. Objective: We aimed to test whether a single motivational lecture could promote weight loss. Methods: Our study was a 3-month randomized controlled trial, and we recruited participants via local newspaper advertisements in 3 cities in Ibaraki Prefecture, Japan, and randomly assigned them to a control group (no intervention) and an intervention group, who attended a single motivational lecture lasting approximately 2 h. No other lectures or textbooks were provided. The eligibility criteria included an age of 40–64 years, a body mass index (BMI) of 25–40 kg/m², and the presence of at least 1 component of metabolic syndrome. The primary outcome was body weight change at 3 months. Results: We enrolled 145 eligible participants with a mean age of 53.8 ± 7.1 years and a BMI of 28.5 ± 3.1 kg/m². The 3-month body weight change in the control and intervention groups was –0.65 kg (95% confidence interval [CI] –1.09 to –0.20) and –2.48 kg (95% CI –3.01 to –1.95), respectively. The between-group difference was 1.83 kg (95% CI 1.15–2.51). Conclusions: The significant difference suggested that a single motivational lecture is an effective option to promote modest weight loss in the short term.