Effect of a Whole Food, Plant-Based Diet on Cardiovascular Risk-Factors Among U.S. Veterans: A Pilot Study

Abstract

Objectives: This study aimed to preliminarily test the effectiveness of a commercial online nutrition program to promote adoption of a whole food, plant-based diet (WFPB) and reduce metabolic cardiovascular risk factors in veterans, compared to the Veterans Affairs (VA) online standard-of-care (SoC) treatment.

Methods: A 12-month randomized controlled trial design was used to pilot this comparison. Veterans with diabetes, hyperlipidemia, hypertension, or overweight/obesity, and an interest and desire to make a lifestyle change were recruited. Veterans were randomized 2:1 to the online WFPB diet treatment arm (WFPB) or the VA standard-of-care (SoC) online weight management program. Baseline anthropometrics, biochemistries, and dietary patterns were measured. Dietary intake was collected using 3-day food records and the 4Leaf survey. Measures were repeated at three, six, and 12 months.

Results: Ninety-two veterans (28% females) were randomized, and 49 completed the study. There was no difference in age (WFPB vs. SoC: 60 Å} 13 vs. 64 Å} 11 years) or baseline metabolic indicators (body mass index: 35 Å} 5 vs. 35 Å} 4 kg/m2; total cholesterol: 181 Å} 51 vs. 171 Å} 41 mg/dL; hemoglobin A1c [HbA1c]: 6.3 Å} 1 vs. 6.4% Å} 1%) between groups (p > 0.05). More females were enrolled in WFPB vs. SoC (34% vs. 8%, p = 0.01). After 12 months, baseline calorie intake from whole plant foods increased from 23% (p > 0.9999) to 36% and 41% in WFPB and SoC, respectively (p = 0.0146). The WFPB group lost more weight over one year compared with SoC (3.4% Å} 4.7% vs. 1.7% Å} 4.9%, p = 0.014). Total cholesterol decreased significantly in WFPB males. High-density lipoprotein cholesterol (HDL-C) increased in the WFPB group. There were no statistically significant changes in blood pressure, low-density lipoprotein cholesterol (LDL-C), or HbA1c in either group.

Conclusions: Both groups increased the percent calories consumed from whole plant foods; the range of change was 20–40%. The WFPB group showed the most rapid change, while the SoC group showed a more gradual but sustained change, resulting in partial convergence of the long-term dietary pattern. This increase did not sufficiently lower LDL-C levels. Other factors, including medication use and small sample size, may have contributed to this result. The WFPB program promoted greater weight loss over 12 months in veterans compared with the current VA SoC. In clinical settings where intensive meal-based programs are not feasible, publicly available online technologies to complement provider interaction offer a promising alternative.