Department of Health Promotion, Education, and Behavior, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA.
Department of Health Promotion, Education, and Behavior, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA.
J Nutr. 2023 Feb;153(2):579-587. doi: 10.1016/j.tjnut.2022.11.020. Epub 2022 Dec 23.
The US Dietary Guidelines (USDG) form the basis of nutrition guidelines, but the research informing the 3 USDG dietary patterns (Healthy US-Style [H-US], Mediterranean [Med], and vegetarian [Veg]) has been drawn largely from observational studies among White populations.
The Dietary Guidelines 3 Diets study was a 3-arm, 12-wk randomly assigned intervention among African American (AA) adults at risk of type 2 diabetes mellitus that tested the 3 USDG dietary patterns.
The AAs (ages 18-65 y, BMI 25-49.9 kg/m, and BMI was measured in kg/m) with ≥3 type 2 diabetes mellitus risk factors were recruited. Weight, HbA1c, blood pressure, and dietary quality (healthy eating index [HEI]) were collected at baseline and 12 wk. In addition, participants attended weekly online classes that were designed using material from the USDG/MyPlate. Repeated measures, mixed models with maximum likelihood estimation, and robust computation of standard errors were tested.
Of the 227 participants screened, 63 were eligible (83% female; age 48.0 ± 10.6 y, BMI 35.9 ± 0.8 kg/m) and randomly assigned to the Healthy US-Style Eating Pattern (H-US) (n = 21, 81% completion), healthy Mediterranean-style eating pattern (Med) (n = 22, 86% completion), or healthy vegetarian eating pattern (Veg) (n = 20, 70% completion) groups. Within-group, but not between groups, weight loss was significant (-2.4 ± 0.7 kg H-US, -2.6 ± 0.7 kg Med, -2.4 ± 0.8 kg Veg; P = 0.97 between group). There was also no significant difference between groups for changes in HbA1c (0.03 ± 0.05% H-US, -0.10 ± 0.05% Med, 0.07 ± 0.06% Veg; P = 0.10), systolic BP (-5.5 ± 2.7 mmHg H-US, -3.2 ± 2.5 mmHg Med, -2.4 ± 2.9 mmHg Veg; P = 0.70), diastolic blood pressure (-5.2 ± 1.8 mmHg H-US, -2.0 ± 1.7 mmHg Med, -3.4 ± 1.9 mmHg Veg; P = 0.41), or HEI (7.1 ± 3.2 H-US, 15.2 ± 3.1 Med, 4.6 ± 3.4 Veg; P = 0.06). Post hoc analyses showed that the Med group had significantly greater improvements in HEI compared to the Veg group (difference = -10.6 ± 4.6; 95% CI: -19.7, -1.4; P = 0.02).
The present study demonstrates that all 3 USDG dietary patterns lead to significant weight loss among AA adults. However, none of the outcomes were significantly different between groups. This trial was registered at clinicaltrials.gov as NCT04981847.
美国膳食指南（USDG）构成了营养指南的基础，但为制定 3 种 USDG 饮食模式（健康的美国式饮食[H-US]、地中海式饮食[Med]和素食[Veg]）提供信息的研究主要来自白种人群的观察性研究。
饮食指南 3 种饮食研究是一项为期 12 周的随机干预研究，针对的是有 2 型糖尿病风险的非裔美国人（AA）成年人，旨在测试 3 种 USDG 饮食模式。
招募了年龄在 18-65 岁之间、BMI 为 25-49.9kg/m²之间且 BMI 以 kg/m²为单位测量的≥3 种 2 型糖尿病风险因素的 AA 成年人。基线和 12 周时测量体重、HbA1c、血压和饮食质量（健康饮食指数[HEI]）。此外，参与者每周参加一次在线课程，这些课程是使用 USDG/MyPlate 的材料设计的。采用重复测量、最大似然估计的混合模型和稳健的标准误计算进行检验。
在 227 名接受筛查的参与者中，有 63 名符合条件（83%为女性；年龄 48.0±10.6 岁，BMI 35.9±0.8kg/m²）并被随机分配到健康的美国式饮食模式（H-US）组（n=21，完成率 81%）、健康的地中海式饮食模式（Med）组（n=22，完成率 86%）或健康的素食饮食模式（Veg）组（n=20，完成率 70%）。组内体重减轻显著（H-US 组为-2.4±0.7kg，Med 组为-2.6±0.7kg，Veg 组为-2.4±0.8kg；P=0.97 组间）。HbA1c 的变化在组间也没有显著差异（H-US 组为 0.03±0.05%，Med 组为-0.10±0.05%，Veg 组为 0.07±0.06%；P=0.10），收缩压（H-US 组为-5.5±2.7mmHg，Med 组为-3.2±2.5mmHg，Veg 组为-2.4±2.9mmHg；P=0.70），舒张压（H-US 组为-5.2±1.8mmHg，Med 组为-2.0±1.7mmHg，Veg 组为-3.4±1.9mmHg；P=0.41），或 HEI（H-US 组为 7.1±3.2，Med 组为 15.2±3.1，Veg 组为 4.6±3.4；P=0.06）。事后分析显示，Med 组的 HEI 改善明显大于 Veg 组（差值为-10.6±4.6；95%CI：-19.7，-1.4；P=0.02）。
本研究表明，所有 3 种 USDG 饮食模式均能使非裔美国成年人显著减轻体重。然而，组间没有任何结果存在显著差异。本试验在 clinicaltrials.gov 上注册为 NCT04981847。
