Declining trends of overweight and obesity in 4-year-olds during 2007-2022 in Northern Sweden

Abstract Background Overweight among preschool children is a huge public health issue. The prevalence of both childhood overweight and obesity increased during the COVID-19-pandemic. Our aim was to study the development of overweight and obesity among 4-year-olds in Västerbotten, Sweden, from 2007 until 2022 with special focus on the COVID-19-pandemic and the year after. Methods This is a repeated cross-sectional study that utilized individual data from most 4-year-old children living in Västerbotten County, Sweden in 2007-2022, implying that the children were born 2003-2108. We included encrypted and anonymized individual anthropometrical data from the routine 4-year-old Child Health Care visit. There were 47 004 4-year-old children living in the county and we included data from 42 584 children, 21 966 boys and 20 618 girls at the age of 46-51 months. Results Overweight and obesity decreased over the study period. In 2007 the prevalence of overweight was 13.4% for boys and 14.9% for girls and obesity 3.7% for boys and 2.7% for girls. In 2022 the prevalence of overweight had declined to 9.5% for boys and 12.1% for girls and the prevalence of obesity to 1.8% and 2.1%, respectively. During the COVID-19-pandemic the prevalence of overweight and obesity for both boys and girls increased and then rapidly returned to the pre-pandemic level in 2022. Conclusions In a setting with free standardized Child Health Care, we present a clear decline in the prevalence of overweight and obesity among Swedish preschool children over time. As in other settings the prevalence of overweight and obesity increased during the COVID-19-pandemic, but we also report a rapid decline in overweight and obesity after the pandemic. It is essential to understand the underlying mechanisms responsible for this favorable trend. Key messages • We present clear decline in the prevalence of overweight and obesity in preschool children over time in a setting with free standardized Child Health Care. • It is important to understand the possible mechanisms of the favorable trend of decrease of the prevalence of overweight and obesity in children pre- and post-pandemic.