Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Sognsvannveien 9, 0372, Oslo, Norway.
Department of Pharmacology, University of Oxford, Oxford, UK.
J Transl Med. 2021 Apr 15;19(1):153. doi: 10.1186/s12967-021-02824-3.
Dietary sulfur amino acid (SAA) restriction is an established animal model for increasing lifespan and improving metabolic health. Data from human studies are limited. In the study outlined in this protocol, we will evaluate if dietary SAA restriction can reduce body weight and improve resting energy expenditure (REE) and parameters related to metabolic health.
METHOD/DESIGN: Men and women (calculated sample size = 60), aged 18-45 years, with body mass index of 27-35 kg/m will be included in a double-blind 8-week dietary intervention study. The participants will be randomized in a 1:1 manner to a diet with either low or high SAA. Both groups will receive an equal base diet consisting of low-SAA plant-based whole foods and an amino acid supplement free of SAA. Contrasting SAA contents will be achieved using capsules with or without methionine and cysteine (SAA, total diet SAA ~ 50-60 mg/kg body weight/day; SAA, total diet SAA ~ 15-25 mg/kg body weight/day). The primary outcome is body weight change. Data and material collection will also include body composition (dual X-ray absorptiometry), resting energy expenditure (whole-room indirect calorimetry) and samples of blood, urine, feces and adipose tissue at baseline, at 4 weeks and at study completion. Measures will be taken to promote and monitor diet adherence. Data will be analyzed using linear mixed model regression to account for the repeated measures design and within-subject correlation.
The strength of this study is the randomized double-blind design. A limitation is the restrictive nature of the diet which may lead to poor compliance. If this study reveals a beneficial effect of the SAA diet on body composition and metabolic health, it opens up for new strategies for prevention and treatment of overweight, obesity and its associated disorders. Trial registration ClinicalTrials.gov: NCT04701346, Registration date: January 8th, 2021.
饮食中硫氨基酸（SAA）限制是一种已被证实的延长寿命和改善代谢健康的动物模型。来自人类研究的数据有限。在本方案中概述的研究中，我们将评估饮食 SAA 限制是否可以减轻体重并改善静息能量消耗（REE）和与代谢健康相关的参数。
方法/设计：纳入年龄在 18-45 岁之间、体重指数为 27-35kg/m 的男性和女性（计算样本量 = 60 人）将参与一项为期 8 周的双盲饮食干预研究。参与者将以 1:1 的比例随机分为 SAA 低或高饮食组。两组都将接受一种低 SAA 的植物性全食物基础饮食和一种不含 SAA 的氨基酸补充剂。通过使用含有或不含有蛋氨酸和半胱氨酸的胶囊来实现 SAA 含量的差异（SAA，总膳食 SAA ~ 50-60mg/kg 体重/天；SAA，总膳食 SAA ~ 15-25mg/kg 体重/天）。主要结局是体重变化。数据和材料收集还将包括身体成分（双能 X 射线吸收法）、静息能量消耗（全室间接测热法）以及基线、4 周和研究结束时的血液、尿液、粪便和脂肪组织样本。将采取措施促进和监测饮食依从性。数据将使用线性混合模型回归进行分析，以考虑重复测量设计和个体内相关性。
该研究的优势在于随机双盲设计。局限性在于饮食的限制性，这可能导致依从性差。如果这项研究表明 SAA 饮食对身体成分和代谢健康有有益的影响，那么它为超重、肥胖及其相关疾病的预防和治疗开辟了新的策略。
ClinicalTrials.gov：NCT04701346，注册日期：2021 年 1 月 8 日。
