A Two‐Year Randomized Weight Loss Trial Comparing a Vegan Diet to a More Moderate Low‐Fat Diet

George Washington University, Washington, Washington, D.C., United States
Obesity (Impact Factor: 3.73). 09/2007; 15(9):2276-81. DOI: 10.1038/oby.2007.270
Source: PubMed


The objective was to assess the effect of a low-fat, vegan diet compared with the National Cholesterol Education Program (NCEP) diet on weight loss maintenance at 1 and 2 years.
Sixty-four overweight, postmenopausal women were randomly assigned to a vegan or NCEP diet for 14 weeks, and 62 women began the study. The study was done in two replications. Participants in the first replication (N = 28) received no follow-up support after the 14 weeks, and those in the second replication (N = 34) were offered group support meetings for 1 year. Weight and diet adherence were measured at 1 and 2 years for all participants. Weight loss is reported as median (interquartile range) and is the difference from baseline weight at years 1 and 2.
Individuals in the vegan group lost more weight than those in the NCEP group at 1 year [-4.9 (-0.5, -8.0) kg vs. -1.8 (0.8, -4.3); p < 0.05] and at 2 years [-3.1 (0.0, -6.0) kg vs. -0.8 (3.1, -4.2) kg; p < 0.05]. Those participants offered group support lost more weight at 1 year (p < 0.01) and 2 years (p < 0.05) than those without support. Attendance at meetings was associated with improved weight loss at 1 year (p < 0.001) and 2 years (p < 0.01).
A vegan diet was associated with significantly greater weight loss than the NCEP diet at 1 and 2 years. Both group support and meeting attendance were associated with significant weight loss at follow-up.

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Available from: Gabrielle Turner-McGrievy
    • "For the omni group, they were considered to be adherent if their energy from fat was ≤ 40%. This method of assessing dietary adherence has been used in previous studies (Barnard, Gloede, et al., 2009; Turner-McGrievy et al., 2007). Percent weight loss at six months among participants who were adherent to their diets (n = 25) and those who were nonadherent (n = 37) was examined among participants instructed to follow a meat-free diet (vegan or veg groups), a diet that allowed moderate intake of meat (pesco-veg or semi-veg), or a diet with unrestricted animal product intake (omni) at six months. "
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    ABSTRACT: The goal of the present study was to examine dietary adherence and acceptability among participants from the New DIETs study who were randomized to one of four plant-based diets (vegan, vegetarian, pesco-vegetarian, semi-vegetarian) or an omnivore diet. Primary outcomes at two- and six months included dietary adherence (24-hour dietary recalls), weight loss and changes in animal product intake (mg cholesterol) by adherence status, Three-Factor Eating Questionnaire (TFEQ), Power of Food Scale (PFS), dietary acceptability (Food Acceptability Questionnaire), and impact of diet preference on adherence. No differences were found in dietary adherence or changes in FAQ, TFEQ, or PFS among the groups. At six months, non-adherent vegan and vegetarian participants (n=16) had a significantly greater decrease in cholesterol intake (-190.2±199.2mg) than non-adherent pesco-vegetarian/semi-vegetarian (n=15, -2.3±200.3mg, P=0.02) or omnivore participants (n=7, 17.0±36.0, P=0.04). Non-adherent vegan/vegetarian participants lost significantly more weight at six months (-6.0±6.7%) than non-adherent omnivore participants (-0.4±0.6%, P=0.04). Dietary preference had no impact on adherence at six months. Due to equal rates of adherence and acceptability among the diet groups, instructing participants to follow vegan or vegetarian diets may have a greater impact on weight loss and animal product intake than providing instruction in more moderate approaches even among non-adherent participants. Copyright © 2015 Elsevier Ltd. All rights reserved.
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    • "MR also differs from restriction of other essential amino acids because it increases food intake relative to body size [5] in contrast to leucine restriction for example, which decreases food intake [6]. Vegetarian diets which are typically low in methionine are associated with reportedly higher metabolic rate [7], lower weight gain in longitudinal studies [8], and greater weight loss in dieters [9]. Thus, MR is attractive in the context of obesity prevention. "
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    • "ão à dieta controle: Intervenção: 8,7% Controle: 7,1% * Analisados somente os pacientes que completaram o estudo Intervenção: 27,1% Controle: 26,5% Registros alimentares de 3 dias quinzenalmente na fase 1 e mensalmente na fase 2, além de escalas analógicas para avaliação de fome, saciedade e questionário específico para grau de satisfação da dieta Turner-McGrievy e cols. Obesity. 2007 (27) n = 64 Mulheres pós-menopáusicas IMC 26-44 kg/m 2 24 meses Dietas sem restrição energética: Tipo vegano com baixo teor de lipídeos: baseada em frutas, vegetais, leguminosas e grãos. Cereais refinados foram desencorajados e produtos animais, excluídos Controle: baseada nas Diretrizes do NCEP ATP III Perda de peso significativa e mai"
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    ABSTRACT: Being overweight is the sixth most important risk factor for chronic non-transmissible diseases. Many publications have been produced in recent years to evaluate the best weight loss alternative. The aim of this systematic review was to critically assess the role of dietary components (macronutrients and/or foods) in weight loss diets in adults recently described in the literature. Randomized clinical trials, with at least one year of follow-up, were selected in MedLine (in Portuguese, English and Spanish languages) from 2004 to 2009. Among the 23 studies included with different types of diets, 13 presented a rate of withdrawal from the study > or = 25% in at least one of the diets. In conclusion, most diets where the weight loss was > 5% of initial weight were energy restricted. Furthermore, following low carbohydrate or Mediterranean diets can be an alternative to isolated energy restriction, but these data are yet to be confirmed.
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