Health, Body Composition, and Nutrition Research Among Women in Kazakhstan

Inclusion Criteria: * Female sex * Age ≥20 years at the time of consent * Natural postmenopause (≥12 consecutive months of amenorrhoea not attributable to other pathological or pharmacological causes) OR surgical postmenopause (bilateral oophorectomy) * Resident of Astana or the surrounding region with no planned relocation during the study period * Able to provide written informed consent independently * Able to complete the questionnaire in Kazakh, Russian, or English Exclusion Criteria: * Active malignancy or systemic anti-cancer treatment (chemotherapy, radiotherapy, immunotherapy) within the past 5 years * Conditions causing secondary changes in muscle mass or body composition: hyperthyroidism (untreated), Cushing's syndrome, acromegaly, severe liver disease (Child-Pugh B or C), advanced chronic kidney disease (Stage 4 or 5, eGFR \<30 ml/min/1.73 m²) * Neuromuscular disorders that independently affect skeletal muscle mass (e.g., myopathy, motor neurone disease, multiple sclerosis) * Long-term systemic corticosteroid therapy (\>3 months in the past year, equivalent to ≥5 mg/day prednisolone) * Severe skeletal deformity (kyphoscoliosis, limb absence) or presence of metallic implants (hip or knee prosthesis on both sides, bilateral rods) that would significantly compromise DEXA body composition validity * Physical inability to stand or to complete the functional assessments safely * Cognitive impairment or psychiatric condition precluding independent informed consent, as…