Participant characteristics and self-reported weight status in a cross-sectional pilot survey of self-identified followers of popular diets: Adhering to Dietary Approaches for Personal Taste (ADAPT) Feasibility Survey

Scoring adherence to voluntary restriction diets (SAVoReD) in the ADAPT study

Voluntary adoption of popular food-group-restricting diets like Paleo and plant-based diets (PBDs) are often health-motivated. However, unlike the theoretical design of these diets, different levels of dietary adherence may result in different diet quality and bodyweight in real-world settings-a limitation to the efficacy of dietary interventions. Scoring Adherence to Voluntary Restriction Diets (SAVoReD) is a metric to quantify and compare adherence across food-group-restricting diets. We applied the score to four diets, whole food plant-based (WFPB), vegan, vegetarian, and Paleo to examine associations between adherence and diet quality (Healthy Eating Index; HEI), body mass index (BMI), and diet duration. We also explored the independent associations of adherence and duration with BMI. Higher adherence to WFPB and vegan diets was significantly associated with lower BMI, but no association was observed for vegetarian or Paleo diet followers. For vegan and WFPB, greater adherence was associated with lower BMI among those following their diet ≥2 years compared to <2 years. Adherence was lowest in the diet with the most restrictions (WFPB); however, the stricter fully plant-based diets (WFPB and vegan) had the healthiest HEI scores and BMIs and many long-term followers. Our results suggest that identification with fully plant-based diets is associated with better diet quality and BMI. Vegan, vegetarian, and WFPB diets are often grouped as 'plant-based diets' despite the differing diet compositions, diet quality, adherence, and BMI of followers-thus, grouping them may distort findings. Individuals may benefit from encouragement following a fully plant-based diet, even without perfect adherence.

The Relevance of Plant-Based Diets and Micronutrient Supplementation for Body Composition: Data from the VeggieNutri Cross-Sectional Study

OBJECTIVES

This study aimed to compare the anthropometry and body composition of vegetarian and omnivorous adults living in Portugal, while exploring nutritional and health parameters underlying observed differences.

METHODS

425 omnivorous (OMNI), lacto-ovo-vegetarian (LOV), or vegan (VEG) healthy adults were recruited. Anthropometry was measured, and bioelectrical impedance analysis was performed. Participants answered food frequency, sociodemographic, and lifestyle questionnaires. Serum iron, ferritin, and CRP were quantified by spectrophotometry, and serum B12 vitamin and homocysteine were quantified by chemiluminescent microparticle immunoassay.

RESULTS

Total protein intake significantly decreased with increasing strictness of vegetarian habits (median (P25; P75) in g/day: 98.6 (79.5; 123.1), 90.4 (65.9; 121.0), and 87.6 (59.8; 118.5) for OMNI, LOV and VEG, respectively; p = 0.020), and carbohydrate intake was the highest in LOV (median (P25; P75) in g/day: 231.5 (178.4; 287.9), 283.9 (227.3; 342.6), and 263.0 (222.0; 348.3) for OMNI, LOV and VEG, respectively; p = 0.001). VEG were the main users of B12 vitamin (93% in VEG vs. 17% in OMNI and 59% in LOV, p = 0.001), and LOV were the main users of iron supplements (29% in LOV vs. 14% in OMNI and 13% in VEG, p = 0.042), respectively. Blood levels of B12 vitamin correlated negatively with blood homocysteine (rs = -0.386, p < 0.001) and positively with % muscle mass (rs = 0.136, p = 0.005). Participants using iron supplements presented higher C-reactive protein (CRP) (p = 0.014) and they had lower % MM (p = 0.003). Finally, when compared to being OMNI, being LOV independently associated with: (a) having +4.8% (p = 0.002) of fat mass, which could be due to higher carbohydrate intake, and (b) having -2.2% (p = 0.043) of muscle mass. Our data suggest that the association between diet and muscle mass could be attenuated in VEG due to B12 supplementation and/or aggravated in LOV due to iron supplementation-associated inflammation.

Nutritional Status and Habits among People on Vegan, Lacto/Ovo-Vegetarian, Pescatarian and Traditional Diets

Background: This study assessed the possible dependencies between nutritional habits and body composition among subjects with different dietary habits. Materials: A total of 196 healthy (aged 18−50 yrs) participants were enrolled in the study and divided into 4 groups according to their diet: vegans-VEGAN (n = 53), lacto/ovo-vegetarians—VEGE (n = 52), pescatarians-PESCA (n = 28), and omnivores-OMN (n = 43). Methods: The Food Frequency Questionnaire (FFQ) was used, and body composition was assessed on the In-Body120 analyzer. Results: Our result revealed in OMN + PESCA groups a higher average consumption frequency of sweets (p = 0.024), cheese/plant cheese (p < 0.001), eggs and egg dishes/egg substitutes (p < 0.001), butter, margarine/plant margarine (p < 0.001), cream /plant cream (p = 0.018), wine and cocktails (p = 0.028), vodka (p = 0.039) and lower of natural cottage cheese/tofu/tempeh (p < 0.001), vegetable oils (p = 0.036), legumes (p < 0.001) and nuts and seeds(p < 0.001) compared to the VEGAN + VEGE groups. The body composition analysis showed significant differences in skeletal muscle mass (SMM) (p = 0.019) and the content of minerals (p = 0.048) between groups. VEGAN disclosed the lowest average values of body fat mass (BFM), percentage body fat (PBF), and visceral adipose tissue (VAT) than other studied groups. Conclusions: The body composition analysis showed mean values within normal ranges in all of the groups, but some average results of OMN, PESCA, and VEGE compared to VEGAN were not highly satisfactory (in addition to eating behavior outcomes).

Comparison between Different Groups of Vegetarianism and Its Associations with Body Composition: A Literature Review from 2015 to 2021

BACKGROUND

Vegetarian and vegan diets have become increasingly popular in the last years for many reasons, including their association with various health benefits when compared to omnivorous diets. The main objective of the study was to collect recent (2015-2021) scientific evidence for potential implications between a vegetarian/vegan diet and an individuals' body composition.

METHODS

A literature search was conducted in PubMed, with 22 studies selected for inclusion in our collective evaluation. Of the 22 studies included, there were 12 randomized controlled trials, 1 nonrandomized controlled trial, 1 comparative study, and 8 cross-sectional. The overall sample included in this study consists of 436,178 participants, 10,090 of whom were vegetarians, 5044 vegans, and 421,044 omnivores.

RESULTS

Most studies, 17 out of 22, reported a significant positive relationship between a plant-based diet and body composition.

CONCLUSION

There is scientifically sound evidence that vegan or vegetarian diets are associated with weight and body mass index reduction and, in some cases, fat mass distribution changes.