Mobile Applet for Weight Management in Obese Heart Failure Patients

Inclusion Criteria: 1. Age ≥18 years; 2. Left ventricular ejection fraction (LVEF) ≤ 50%, with New York Heart Association (NYHA) class II-III; 3. Body mass index (BMI) ≥ 26 kg/m² or male waist-to-hip ratio (WHR=waist circumference/hip circumference) ≥ 0.9, female waist-to-hip ratio ≥ 0.85; 4. Ability to use a smartphone and demonstrate compliance via a diet management mobile application during a 2-week ±1-week run-in period; 5. History of heart failure hospitalization within the past 6 months; 6. Signed informed consent. Exclusion Criteria: 1. End-stage heart failure (≥2 hospitalizations for heart failure in the past 3 months, intolerance to guideline-directed medical therapy (GDMT), or dependence on inotropic agents); 2. Heart failure with reversible causes (e.g., peripartum cardiomyopathy, fulminant myocarditis); 3. Moderate or severe anemia (hemoglobin \[Hb\] \<90 g/L); 4. Renal insufficiency (estimated glomerular filtration rate \[eGFR\] \<30 mL/min/1.73 m²) or ongoing dialysis; 5. Uncontrolled thyroid disease (hyperthyroidism/hypothyroidism) or end-stage liver failure; 6. Alcohol or substance abuse; 7. Current use of weight-loss medications or planned bariatric surgery; 8. Malignancy with an expected survival \<1 year; 9. Conditions potentially hindering protocol compliance, as judged by the investigator (e.g., habitual reliance on food delivery services or company cafeteria meals); 10. Planned hospitalization during the trial period; 11. Concurrent participation in another interventional clinical study.