The objective of this clinical trial is to investigate the effect of weight reduction through a diet management application and an intelligent weight scale on a composite cardiovascular endpoint in obese patients with heart failure.

The main questions are:

Does the use of a diet management APP and intelligent weight scale reduce 1-year all-cause mortality, heart failure hospitalization, and first heart failure hospital stay? Does the use of a diet management APP and intelligent weight scale improve the outcomes of assessment of heart failure frailty and quality of life for heart failure?

Researchers will compare using the fully functional diet management app and intelligent weight scale to using the limitedly functional app and intelligent weight scale to see if the app works to improve heart failure conditions.

Participants will:

Use the diet management app at every meal and the intelligent weight scale every day for 12 months, and visit the clinic at 12 months for checkups.

Obesity is one of the major risk factors for heart failure. Current guidelines for heart failure emphasize that severe obesity is associated with a poor prognosis in patients with heart failure, but there are no recommended effective interventions.

Caloric restriction alone, increased exercise, the use of weight-loss drugs, and bariatric surgery are not appropriate for obese patients with heart failure.

Whether obese heart failure patients with reduced ejection fraction (HFrEF) can benefit from weight loss treatment has not been evaluated in randomized controlled trials so far.

This study combines caloric restriction with lifestyle management to help HFrEF patients lose weight.

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.