© 2022 Elsevier LtdIntroduction: COVID-19 is currently a global pandemic, and initial reports of identified COVID-19 lockdown and limitations can adversely affect childhood obesity and metabolic health. Studies conducted in recent years have shown that the rate of obesity in childhood increases with the changing lifestyle with the pandemic. However, there is insufficient data on how the situation changes and how metabolism is affected in those, who are already obese. The aim of this paper was to determine how the pandemic affects the current status, severity, and metabolic parameters of obese children. We also attempted to show potential effects of metformin therapy. Methods: The study was conducted with the participation of 101 patients with obesity (The mean age was 13.6 ± 2.2). The patients were evaluated using pre- and post-lockdown data with an interval of 6 months. The new classification system was used to determine the severity of obesity. All anthropometrics, metabolic parameters (Blood glucose, insulin, HbA1C, lipid profile), lifestyle, and comorbidities were evaluated by dividing the participants into various subgroups according to their obesity and metformin usage status. Results: Our data shows that weight, height, BMI, BMI-SD, and BMI percentiles all increased significantly, after the pandemic started. The severity of obesity increased statistically (overweight decreases and class 2 obesity increases, p = 0.001). No change was observed in metabolic parameters. Surprisingly, a significant increase was observed in insulin and HOMA-IR values in the group with-metformin. Discussion: Most studies about childhood obesity have only focused on obesity increases and pandemic relation. Our study showed that although there was no significant change in metabolic status at the end of a lockdown period, there was a serious increase in the severity of obesity. Metformin use had no effect on either obesity or metabolic parameters, and even an increase in insulin resistance indicators was observed.