Ceramide d18:1/24:1 as a potential biomarker to differentiate obesity subtypes with unfavorable health outcomes.

"Declarations Ethics approval and consent to participateThis study protocol was approved by the Institutional Review Board of the First Affiliated Hospital of Nanjing Medical University, and all participants provided written informed consent (2014-SR-003) prior to study entry. Consent for publicationNot applicable. Competing interestsThe authors declare that they have no competing interests. Competing interests The authors declare that they have no competing interests."

"Funding This study was supported by the National Key R&D Program of China [2019YFA0802701, 2018YFA0506904], the National Natural Science Foundation of China [91854122, 31900832, 82170882, 82270921], and the Jiangsu Science and Technology Office [BK20191074]. This project was also supported by Shanghai Qi Zhi Institute (SYXF0120020601), Jiangsu Provincial Medical Key Discipline(Laboratory) (ZDXK202202), and the Priority Academic Program Development of Jiangsu Higher Education Institutions."

"Trial registration The First Affiliated Hospital of Nanjing Medical University’s Institutional Review Board authorized this study protocol, and all participants provided written informed consent (2014-SR-003) prior to study entry."