Abstract 2511: Does Adherence to a Lacto-Ovo-Vegetarian Diet Affect Weight Loss?
Observational studies have found numerous benefits to eating a vegetarian diet, including weight loss maintenance. A central aim of the PREFER study, a clinical trial of a behavioral intervention for weight loss, was to examine differences in weight loss between subjects who were randomly assigned to a behavioral intervention and to one of two calorie- and fat-restricted diets: standard (STD) and lacto-ovo-vegetarian (LOV). Of 176 participants (44.0 ± 8.8 years, 87% females, 71% Caucasian), 96 were assigned to STD and 80 to LOV. At 18 months, both diet groups experienced significant weight loss compared to baseline values (mean wt. loss: STD = 10.4 ± 14.7 lbs; LOV = 11.2 ± 15.0 lbs). We evaluated the LOV subjects further by dietary adherence at 18 months, which was defined as reporting following a meatless meal plan (no meat, poultry or fish) on the Three-day Food Record (adherent n = 44; not adherent n =36). There were no significant differences in sociodemographic characteristics between the adherent and non-adherent groups. We found a significant difference in weight loss between those who were adherent and those who were non-adherent to the LOV diet: adherent −16.5 ± 16.9 lbs. vs. non-adherent −4.8 ± 8.8 lbs, p <.001. Also, there were significant differences between the adherent and non-adherent groups in macronutrient consumption: kilocalories (1452.3 ± 365.5 vs.1685.9 ± 508.1, p < .02), fat grams (41.0 ± 15.0 vs. 61.0 ± 22.5 p <.001), saturated fat grams (13.4 ± 5.8 vs. 20.8 ± 10.4, p = .005), carbohydrate grams (221.8 ± 57.3 vs. 205.7 ± 68.4, p = .37), and protein grams (54.3 ± 17.5 vs. 65.5 ± 22.1, p = .06). Despite the improved dietary intake and weight loss among the adherent group, similar improvements were not observed in serum lipids at 18 months. In conclusion, in the first testing of a LOV diet for weight loss, our results indicate that implementing and facilitating long-term adherence to a LOV diet may be beneficial for weight loss and reducing dietary fat intake.