Introduction
Well-planned vegan and vegetarian diets can provide
adequate nutrition, and have demonstrated health benefits in
disease prevention and treatment [1]. Vegan and vegetarian diets
have been used effectively for weight loss and maintenance
[2,3]. Anchoring the two ends of the plant-based dietary spectrum
are vegan diets (exclude all animal products) and omnivorous
diets (omni: no foods excluded). Between these two diets
are other plant-based diets, such as semi-vegetarian (semi-veg:
occasional meat intake), pesco-vegetarian (pesco-veg: excludes
meat except seafood), and vegetarian (veg: excludes all meat and
seafood, but contains eggs and dairy products). Several epidemiologic
studies have examined differences in weight-related
outcomes among these diets, finding lower body weights [4]
and less weight gain over time among vegans compared with
other groups [5].
These prospective cohort studies [4,5] examining the five
diets along the plant-based dietary spectrum have categorized
participants according to their preexisting dietary patterns,
making it difficult to account for the inherent differences that
may exist among individuals who self-select different patterns.
To date, there have been no randomized trials comparing the
effectiveness of these five different diets on weight loss. Therefore,
the goal of this study was to examine the differences in
weight loss among participants randomized to adopt an
omnivorous, semi-vegetarian, pesco-vegetarian, vegetarian, or
GTM and SW designed the research study. GTM, EEW, and CRD conducted the
research. EAF performed statistical analysis. GTM, SW, and EAF wrote the paper.
GTM had primary responsibility for final content. The authors have no conflicts
of interest to declare.
* Corresponding author. Tel.: þ1 803 777 3932; fax: þ1 803 777 6290.
E-mail address: Brie@sc.edu (G. M. Turner-McGrievy).
http://dx.doi.org/10.1016/j.nut.2014.09.002
0899-9007/ 2015 Elsevier Inc. All rights reserved.
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Nutrition
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