Unsaturated Fatty Acids Enriched-diet to Improve Cardiorespiratory Fitness, Metabolic Flexibility and Glucose Tolerance in Obese Patients

Unsaturated Fatty Acids Enriched-diet to Improve Cardiorespiratory Fitness, Metabolic Flexibility and Glucose Tolerance in Obese Patients: a Feasibility Study

The investigators hypothesize that a dietary intervention aimed at increasing unsaturated fatty acids (UFA) consumption is feasible and has the potential to improve cardiorespiratory fitness, metabolic flexibility and glucose tolerance in symptomatic obese heart failure with preserved ejection fraction (HFpEF) patients.

Twelve obese HFpEF subjects with exercise intolerance (reduce cardiorespiratory fitness measured at maximal cardiopulmonary exercise test [CPX]) will be assigned to a single-arm open-label dietary intervention in which subjects are encouraged and financially supported to increase daily UFA consumption. The investigators will measure dietary compliance with a validated 24-hour dietary recall and with objective operator-independent biomarkers of UFA consumption.

The investigators will also measure the effects of UFA supplementation on: metabolic flexibility, glucose tolerance and body composition. Participants will have the option to participate in overnight session in the whole indirect calorimeter room (WIC) at baseline and at the end of the study.

Major Inclusion Criteria:

• Body Mass Index (BMI) ≥30 kg/m2 (obesity) or total body fat percentage >25% in men and >35% in women
• A confirmed clinical diagnosis of stable HF (New York Heart Association [NYHA] class II-III) on maximally tolerated heart failure (HF) optimal medical regimen (without major changes in the prior month)
• Left Ventricular Ejection Fraction (LVEF)>50% documented in the prior 12 months

Major Exclusion Criteria:

• Concomitant conditions or treatment which would affect completion or interpretation of the study (i.e.,physical inability to walk or run on treadmill);
• Significant ischemic heart disease, angina, uncontrolled arterial hypertension, atrial fibrillation, moderate to severe valvular disease, chronic pulmonary disease, anemia (Hemoglobin<10 g/dL)
• Electrocardiography (ECG) changes (ischemia or arrhythmias) that limit maximum exertion during cardiopulmonary exercise test
• Comorbidity limiting survival
• Stage IV-V kidney disease (estimated Glomerular Filtration Rate<30)
• Fluid overload
• Pregnancy
• Current use of unsaturated fatty acids (UFA) supplement (i.e., omega-3).
• Inability to give informed consent