{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T12:55:02Z","timestamp":1782910502795,"version":"3.54.5"},"reference-count":35,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T00:00:00Z","timestamp":1782864000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Public Health"],"abstract":"\n Background<\/jats:title>\n Existing studies on body mass index (BMI) among university students have largely focused on short-term changes during the Coronavirus Disease 2019 (COVID-19) pandemic, with limited evidence on long-term trajectories across different pandemic phases. Therefore, this study aimed to evaluate trends in BMI and overweight prevalence among Chinese university freshmen from 2016 to 2024 using repeated cross-sectional data and to quantify both the immediate and sustained effects of COVID-19 policy transitions.<\/jats:p>\n <\/jats:sec>\n \n Methods<\/jats:title>\n Anthropometric data were collected from successive cohorts of freshmen from a Chinese university between 2016 and 2024. BMI was calculated and categorized into overweight and non-overweight groups. Long-term trends in BMI and overweight prevalence were assessed using linear and non-linear models. Interrupted time series (ITS) analysis was further applied to evaluate changes across the pre-, during-, and post-pandemic periods. Subgroup analyses were conducted by sex and academic discipline.<\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n \n A total of 39,478 freshmen were included. Overall, a rising trend in BMI and overweight prevalence was observed among university students over the study period. Crude ITS analysis showed that BMI increased gradually before the pandemic (\n \u03b2<\/jats:italic>\n 1<\/jats:sub>\n \u202f=\u202f0.096\u202fkg\/m\n 2<\/jats:sup>\n \/year,\n p<\/jats:italic>\n \u202f&lt;\u202f0.001), followed by a temporary slowdown during the pandemic period (\n \u03b2<\/jats:italic>\n 4<\/jats:sub>\n \u202f=\u202f\u22120.222\u202fkg\/m\n 2<\/jats:sup>\n \/year,\n p<\/jats:italic>\n \u202f&lt;\u202f0.001). In the post-pandemic period, BMI and overweight prevalence increased markedly, characterized by a significant upward slope change (\n \u03b2<\/jats:italic>\n 5<\/jats:sub>\n \u202f=\u202f0.738\u202fkg\/m\n 2<\/jats:sup>\n \/year,\n p<\/jats:italic>\n \u202f=\u202f0.001) reaching the highest levels in 2024. Males exhibited a higher prevalence of overweight and a steeper post-pandemic increase than females. Discipline-specific differences demonstrated that humanities, arts and social sciences (HASS) students had a more immediate change. In contrast, science, technology, engineering, and mathematics (STEM) students exhibited a more sustained increase over time.\n <\/jats:p>\n <\/jats:sec>\n \n Conclusion<\/jats:title>\n BMI trajectories were significantly altered by the pandemic, with a marked post-pandemic acceleration exceeding pre-existing trends. Future longitudinal studies are needed to clarify the behavioral mechanisms underlying these trends.<\/jats:p>\n <\/jats:sec>","DOI":"10.3389\/fpubh.2026.1856579","type":"journal-article","created":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T12:36:38Z","timestamp":1782909398000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Trends in overweight prevalence among university freshmen and the impact of the COVID-19 pandemic: a repeated cross-sectional study"],"prefix":"10.3389","volume":"14","author":[{"given":"Jiechen","family":"He","sequence":"first","affiliation":[{"name":"Faculty of Health Sciences, University of Macau","place":["Taipa, Macao SAR, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xuan","family":"Yin","sequence":"additional","affiliation":[{"name":"Faculty of Health Sciences, University of Macau","place":["Taipa, Macao SAR, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jianguang","family":"Ji","sequence":"additional","affiliation":[{"name":"Faculty of Health Sciences, University of Macau","place":["Taipa, Macao SAR, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhifeng","family":"Zhang","sequence":"additional","affiliation":[{"name":"Public Physical Education Department, Hebei North University","place":["Zhangjiakou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,7,1]]},"reference":[{"key":"ref1","year":"2025"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"1027","DOI":"10.1016\/S0140-6736(23)02750-2","article-title":"Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and 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