Background: Obesity is defined as the excessive accumulation of adipose tissue resulting from an imbalance between energy intake and expenditure. This pervasive global health challenge affects a population exceeding 2 billion individuals. In addition, green tea, renowned for its health-promoting properties, is being explored as a potential component in weight management interventions for individuals grappling with excess weight. It is noteworthy for its elevated levels of catechins, specifically Epigallocatechin-3-gallate (EGCG), and caffeine, both of which are posited to exert a beneficial influence on energy expenditure. Methods: The search methodology was applied to two databases, namely PubMed and Medline. The search query incorporated the following keywords: (((Green tea) OR (Polyphenols)) OR (Catechins)) AND (weight loss). The selection of studies adhered to the guidelines outlined in the Preferred Reporting Items for Systematic Reviews (PRISMA, 2020) resulting in six RCTs included. Results: Six studies investigating the effects of green tea on weight management yielded diverse results: one study observed no substantial weight change, another noted weight reduction in individuals with central obesity, a different study found weight loss associated with low-dose catechin consumption, another reported weight decrease in overweight women diagnosed with PCOS, one trial documented weight loss linked to green tea extract supplementation, and the final study indicated a significant reduction in weight in individuals receiving both green tea extract and engaging in endurance training. Conclusion: The findings of randomized controlled trials (RCTs) investigating the impact of Green Tea Extract (GTE) on weight reduction suggest potential effectiveness in the short term, especially with higher doses, particularly within specific subpopulations like overweight individuals, those with central obesity, and individuals with Polycystic Ovarian Syndrome (PCOS). Nevertheless, uncertainties exist regarding the long-term effects and broader applicability of these results due to variations in outcomes across diverse populations, varying study durations, and the intricate interplay of factors including dosage, individual metabolic health, and specific health conditions. Consequently, further research is imperative to gain a comprehensive understanding of how green tea influences weight, waist circumference, and fasting insulin levels metabolically.