INTRODUCTION: Obesity is a critical health condition associated with high rates of morbidity and mortality. Conservative therapies such as dietary restriction, physical exercise, and pharmacological treatments have not prevented the rising incidence of obesity. Bariatric surgery, while effective, is limited to a relatively small proportion of the global obese population due to its strict indications and the risk of early and late postoperative complications. To address this gap, bariatric endoscopy therapies have emerged, offering less invasive, reversible, repeatable, and more cost-effective treatment options. The introduction of the intragastric balloon (IGB) in the 1980s marked the development of a minimally invasive, non-surgical, and safe procedure with low complication rates. OBJECTIVE: To evaluate the weight loss efficacy in overweight and Class I obese patients through the implantation of a 12-month non-adjustable intragastric balloon. METHODS: This prospective study involved overweight patients (BMI \> 27 kg/m²) undergoing intragastric balloon treatment and multidisciplinary follow-up at the Bariatric Endoscopy Clinic of the Faculty of Medicine of ABC (FMABC) over a 12-month period. EXPECTED RESULTS: Weight loss following intragastric balloon implantation and improvement in metabolic indices.