Rationale and Design of a Parallel Randomized Trial of a DASH‐Enhanced Portfolio Diet With or Without Ultra‐Processed Plant Proteins for Blood Pressure and Other Cardiometabolic Risk Factors in Adults With Hypertension and Obesity: The Substitution of High With Low Ultra‐Processed Soy Protein Foods in a Guideline‐Based Diet Intervention on Cardiometabolic Health Trial

BACKGROUND: Cardiovascular disease remains the leading cause of death and hospitalization globally. Clinical practice guidelines recommend various plant-based dietary patterns that target specific cardiometabolic risk factors, including the Dietary Approach to Stop Hypertension (DASH) diet for blood pressure and the Portfolio diet for low-density lipoprotein cholesterol. Combining key elements of these patterns may enhance cardiovascular disease risk reduction. However, many soy-based products, a key Portfolio component, are classified as ultra-processed foods (UPFs). This trial will answer 2 questions: (1) Does a DASH-enhanced Portfolio diet result in clinically meaningful reductions in blood pressure compared with standard of care and (2) Is a high-UPF noninferior to a low-UPF soy protein-containing DASH-enhanced Portfolio diet for blood pressure reduction? METHODS: The SWITCH (Substitution of High With Low Ultra-Processed Soy Protein Foods in a Guideline-Based Diet Intervention for Cardiometabolic Health) trial is a parallel, randomized, 3-arm, open-label, superiority-noninferiority trial. Three hundred adults with hypertension and obesity, including 50% with type 2 diabetes, will be randomized to a high-UPF or low-UPF soy protein-containing DASH-enhanced Portfolio diet or standard of care for 12 weeks. The primary outcome is systolic blood pressure. Key secondary outcomes are non-high-density lipoprotein cholesterol and body weight. Other outcomes include cardiometabolic risk factors. CONCLUSIONS: Findings will provide high-quality evidence on the use of a DASH-enhanced Portfolio diet and the role of nutrient-dense soy foods classified as UPFs within the combination of the 2 guideline-based dietary patterns to support dietary strategies for cardiometabolic risk reduction. REGISTRATION: URL: https://clinicaltrials.gov/; Unique identifier: NCT06907862.