Pulses: Optimizing Pulse Consumption for Cardiometabolic Health

Pulses: Optimizing Pulse Consumption for Cardiometabolic Health

This randomized clinical trial aims to evaluate the effects of consuming two different doses of pulses (1.5 cups/week or 3 cups/week) in individuals with baseline intake below 1.5 cups/week, compared to a control group receiving standard nutrition education based on the United States Department of Agriculture's (USDA) My Plate guidelines.

The main question the Pulses study aims to answer is:

• What is the effect of increasing pulse consumption (in a dose-response manner) on specific cardiometabolic risk factors, including LDL-C, CRP, HBA1C, and blood pressure compared to standard nutrition education?

For secondary outcomes, this study aims to answer the following:

• Does increased pulse consumption improve the following: overall serum lipid profile (Total cholesterol (TC), HDL-C, Triglycerides (TG), diet quality (measured by the Healthy Eating Index), and participants self-reported satisfaction with life (SWLS) and Satisfaction with Food-related Life (SWFoL).

All participants will attend biweekly classes and food demonstrations. The pulses groups will learn to prepare various pulse-based recipes, while the control group will receive guidance on preparing healthy meals following the USDA MyPlate recommendations.

This is a randomized, parallel-arm study with 3 groups: 1) Control (Con). This group will receive educational materials and attend a series of 6 cooking classes focused on the USDA's MyPlate guidelines; 2) Pulses 1.5. This group receive nutrition education and attend a series of 6 cooking classes focused on both USDA's MyPlate guidelines, with a specific emphasis on how to incorporate more pulses into their diet. They will also receive 1.5 cup-equivalents of pulses per week for 6 weeks to take home with them to prepare and eat; 3) Pulses 3.0.

This group will receive the same nutrition education and cooking classes as the Pulses1.5 group, but will be provided with 3.0 cup equivalents of pulses to prepare and eat per week. Participants will be randomized after baseline testing. RedCap will be used to randomly assign participants to a treatment sequence. The randomization ratio will be balanced (balanced by gender and number of participants in each group). Intervention periods must be at least 12 weeks, however participants may continue the intervention for up to 14 weeks total (as is indicated in the informed consent). The range of 12-14 weeks is designed to accommodate for scheduling challenges that may occur due to illness, travel, etc. For example, if a participant completes 12 weeks of the intervention but then is unable to come in for an endpoint visit immediately, we will be able to continue the intervention until they are available for testing. The 12-14 week range will help to accommodate for these scheduling requirements.

Screening: Participants will be screened via an online REDCap survey including demographic and eligibility questions. Individuals who qualify for participation in the study will be invited to schedule a baseline testing visit in our nutrition research center.

Baseline and Week-12 Visits: At the baseline visit, participants will sign an IRB-approved informed consent form. At both visits, following an overnight fast, a blood draw will be completed, and height, weight, and vital signs will be determined. Premenopausal women will be asked to come in for endpoint visits at same point in their menstrual cycle (within the same 5-7 day window) as their baseline visit. In addition, participants will complete questionnaires to assess satisfaction with life and their diet.

• Blood Sampling: A fasting blood draw will be performed at each assessment to measure biomarkers of cardiometabolic health (including but not limited to): total cholesterol (TC), triglycerides (TG), HDL-C, LDL-C, HbA1c, and CRP. Values will be determined according to standardized procedures via Quest Diagnostics.
• Blood Pressure: Brachial blood pressure (BP) will be assessed under standardized conditions using an automated cuff. The BP measurements will be taken following the Joint National Committee 7 (JNC7) blood pressure guidelines in a quiet, temperature-controlled, dimly lit room following a 5-minute seated rest period, asking them not to use their phones, not to talk, and not to cross their legs. 3 measurements will be made, with 30 seconds rest in between, and the average will be calculated.

Questionnaires:

• Satisfaction with Food-related Life (SWFoL) scale: This scale consists of five items, grouped into a single dimension, that evaluate a person's overall assessment of their food and eating habits (e.g., "Food and meals bring great satisfaction to my daily life").
• Satisfaction with Life Scale (SWLS): This scale consists of five items, grouped into a single dimension, which evaluate overall cognitive judgments about a person's own life (e.g., "In most ways my life is close to my ideal").
• International Physical Activity Questionnaire (IPAQ): This questionnaire assesses the amount of time spent being physically active during the last seven days, grouped into vigorous, moderate, walking, and sitting categories.

Dietary Assessment: At baseline, participants will be instructed to maintain their regular caloric intake. At both baseline and at 12 weeks, participants will complete a 3 day dietary record to assess their dietary intake. At each timepoint (baseline and 12 weeks), dietary records will be conducted on 3 separate days to capture their average intake over a week. Baseline 3-day dietary records will be performed before the first cooking class to determine habitual dietary intake. The other records will be completed within a week of the week-12 visit. Diet quality will be calculated based on the nutrient intake data. NPCR program will be used to analyze the dietary intakes. HEI-2020 scores will be calculated to measure diet quality and assess alignment with the 2020-2025 DGA.

Dietary Intervention: All participants will attend biweekly cooking classes and food demonstrations at Tucson Village Farm (TVF), a working farm with a teaching kitchen where staff regularly provide direct education to community members related to growing and preparing food to support overall health. During the class, participants in the MyPlate (control) group will receive nutrition education in alignment with standard MyPlate (i.e., a nutrition education tool for consumers based on the DGA) messages while participants in the pulse intervention groups will receive that information plus additional content and messages focused on pulses. At each class, a recipe, inspired by MyPlate, will be prepared and tasted by participants.

Participants will receive a 2-week supply of pulses to take home with them at these classes, one week of cooked, and one week of dry pulses. This balance of pulse forms was selected to enhance acceptability and convenience and improve self-stability. Participants in the Pulses1.5 and Pulses3.0 groups will also be asked to complete a weekly consumption log to track their consumption of the pulses that were provided at the cooking class. They will be asked to return this log at the following cooking class.

The Healthy US-Style Dietary Pattern of the DGA recommends 1.5 cup-eq of pulses each week for a 2000-calorie dietary pattern. Pulse doses will be adjusted for a participant's caloric needs. Each participant's caloric needs will be estimated using a mathematical formula. For example, a participant in the Pulses group who needs 1600 calories/day will receive 1 cup-eq of pulses each week and a participant who needs 3000 calories/day will receive 3 cup-eq of pulses each week. Similarly, a participant in the Pulses Plus group who needs 1600 calories/day will receive 2 cup-eq of pulses each week and a participant who needs 3000 calories/day will receive 6 cup-eq of pulses each week.

Any adverse events and/or changes in medication during the study will be recorded.

Inclusion Criteria:

• ≥ 18 years old (with no upper age limit)
• Currently consuming less than 1.5 cup-equivalents of pulses per week
• Willing and able to participate in a 12-week dietary intervention focused on increased pulse consumption
• Able to communicate in English and provide written informed consent
• Assessed as suitable to participate in a nutrition intervention by the study dietitian or primary healthcare provider

Exclusion Criteria:

• Individuals already consuming >150 minutes/week of pulse-based dietary programming or otherwise regularly meeting high pulse intake benchmarks at baseline
• Patients with food allergies or intolerances that preclude the consumption of pulses
• Individuals who have not received clearance from their healthcare provider to make significant dietary modifications
• Participants anticipating major changes in dietary habits due to elective surgery, planned relocation, or other lifestyle alterations during the study period (12 weeks)