Introduction:
Over the past few years, there have been noticeable negative changes in lifestyle, further worsened by the SARS-CoV-2 pandemic. These changes, along with reduced physical activity, limited peer interaction, and stress have all contributed to a positive energy balance in a significant group of children. The “Growing Healthy” project, conducted in collaboration with the Health Department of the Łódzkie Voivodeship Office, was aimed to assess the nutritional status of children in the Łódzkie Voivodeship.

Material and methods:
The project included five primary schools selected from the Łódzkie Voivodeship and located in Bełchatów, Koluszki, Łódź, Sieradz, and Skierniewice. A total of 2,904 students attending grades 1–8 were registered. Parents of 1,378 children gave informed consent to participation in the study on behalf of their children. The study subjects were measured for height, weight, hip circumference, and waist circumference in accordance with the approved methods. Based on the collected data, the body mass index (BMI), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR) were calculated. All the measurements were plotted on the OLAF and OLA percentile charts. The project was carried out by the staff of the Department of Pediatrics, Neonatal Pathology and Metabolic Bone Diseases, Medical University of Lodz between September and December 2022.

Results:
A total of 1,378 subjects aged 6–14 years were examined, which accounted for 47% of all the children attending the schools included in the study. The mean age was 9.3 ±1.78 years. The mean BMI percentile for the whole study population was 52.46 ±30.45. Children with underweight constituted 4.1% (n = 56), those with overweight 13.8% (n = 187), and those with obesity 8.2% (n = 111). Abdominal obesity, assessed based on WHtR, was diagnosed in 11.7% (n = 162) of the children. Android abdominal obesity, identified based on WHR, was found in 5% (n = 331) of the girls and only 1.5% (n = 11) of the boys.

Conclusions:
The assessment of excess body weight should be based on several complementary methods of anthropometric measurement as such an approach facilitates the diagnosis. The “Growing Healthy” project keeps evolving and is still being continued in other forms. The study results indicate that obesity and overweight in children in the Łódzkie Voivodeship are a major public health problem/issue, therefore actions in health policy should be taken at the administrative level.