This study aims to assess the effects of environmental pollution (including environmental indicators such as PM2.5, PM5, PM10, SO2, NOX, O3, and greening index) on obese patients and to explore the possible mechanisms by which environmental pollution promotes obesity.

Firstly, the effects of environmental pollution on obese patients were investigated by analysing the baseline conditions and obesity levels (including BMI, waist circumference, hip circumference, etc.) and underlying diseases of obese patients in regions with different pollution levels. Secondly, the association between environmental pollution levels on blood test characteristics (including renal function, sex hormones, glucose tolerance test, trace elements, liver function and blood routine) of obese patients was investigated to find possible mechanisms.

Inclusion Criteria:

• Age ≥18 years;
• obese patients with BMI ≥30;
• patients without surgical treatment prior to enrolment;
• willingness to participate in the study and sign an informed consent form;
• complete clinical data.

Exclusion Criteria:

• patients with systemic diseases such as severe cardiorespiratory insufficiency affecting the choice of treatment regimen;
• patients assessed by the investigator to be inappropriate for enrolment;
• patients with incomplete clinical data.

This is a retrospective observational study, which is expected to include patients diagnosed with obesity ( body mass index (BMI) ≥ 28 kg/m2).

Ethics committees of the clinical centres where the studies were conducted did not allow the release of patient data.