Background: Only a few randomized dietary intervention studies that investigated the effects of lacto-ovo vegetarian diet (Vd) in clinically healthy omnivorous subjects are available.
Methods: We randomly assigned to overweight omnivores with a low-to-moderate cardiovascular risk profile a low-calorie Vd compared with a low-calorie Mediterranean diet (MD), each lasting 3 months, with a crossover design. The primary outcome was the difference in body weight, body mass index, and fat mass changes between the 2 groups. Secondary outcomes were differences in circulating cardiovascular disease risk parameters changes between the 2 groups.
Results: One hundred eighteen subjects (mean age: 51.1 years, females: 78%) were enrolled. The total participation rate at the end of the study was 84.7%. No differences between the 2 diets in body weight were observed, as reported by similar and significant reductions obtained by both Vd (-1.88 kg) and MD (-1.77 kg). Similar results were observed for body mass index and fat mass. In contrast, significant differences between the 2 interventions were obtained for low-density lipoprotein cholesterol, triglycerides, and vitamin B12 levels. The difference between the Vd and MD groups, in terms of end-of-diet values, was recorded at 9.10 mg/dL for low-density lipoprotein cholesterol (P=0.01), 12.70 mg/dL for triglycerides (P<0.01), and 32.32 pg/mL for vitamin B12 (P<0.01). Finally, no significant difference was found between Vd and MD interventions in oxidative stress markers and inflammatory cytokines, except for interleukin-17, which improved only in the MD group. Forty-six participants during the Vd period and 35 during the MD period reached the target values for ≥1 cardiovascular risk factor.
Conclusions: Both Vd and MD were effective in reducing body weight, body mass index, and fat mass, with no significant differences between them. However, Vd was more effective in reducing low-density lipoprotein cholesterol levels, whereas MD led to a greater reduction in triglyceride levels.
Clinical trial registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02641834.
Keywords: Mediterranean; cardiovascular disease; diet; vegetarian.
© 2018 American Heart Association, Inc.