Sciarrillo Christina M, Guo Juen, Hengist Aaron, Darcey Valerie L, Hall Kevin D
National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, USA.
medRxiv. 2023 Oct 4:2023.10.03.23296501. doi: 10.1101/2023.10.03.23296501.
Crossover studies can induce order effects, especially when they lack a wash-out period.
To explore diet order effects on energy balance and food intake between randomized diet order groups in two inpatient crossover studies originally designed to compare within-subject differences in energy intake between either minimally processed low carbohydrate (LC) versus low fat (LF) diets or macronutrient-matched diets composed of mostly minimally processed food (MPF) or ultra-processed food (UPF).
Diet order group comparisons of changes in body weight, body composition, and differences in energy expenditure, and food intake were assessed over four weeks in 20 adults randomized to either the LC followed immediately by the LF diet (LC→LF) or the opposite order (LF→LC) as well as 20 adults randomized to either the MPF followed by UPF (MPF→UPF) diets or the opposite order (UPF→MPF).
Subjects randomized to LC→LF lost 2.9 ± 1.1 kg more body weight ( < 0.001) and 1.5 ± 0.6 kg more body fat ( = 0.03) than the LF→LC group likely because the LC→LF group consumed 922 ± 304 kcal/d less than the LF→LC group ( = 0.0024). Reduced energy intake in LC→LF LF→LC was driven by the last two weeks (-1610 ± 306 kcal/d; <0.00001) perhaps due to carryover effects of gut adaptations over the first two weeks arising from large differences in the mass of food (1295 ± 209 g/d; <0.00001) and fiber intake (58 ± 5 g/d; <0.00001). There were no diet order effects on energy intake, body weight, or body composition change between UPF→MPF versus MPF→UPF groups.
Diet order influences daily energy intake, body weight change, and fat change within the context of a 4-week crossover inpatient diet study varying in macronutrients, but not varying in extent and purpose of processing.
Intramural Research Program of the National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health.
NCT03407053 and NCT03878108.
交叉研究可能会引发顺序效应，尤其是在缺乏洗脱期的情况下。
在两项住院患者交叉研究中，探讨饮食顺序对随机分组的饮食顺序组之间能量平衡和食物摄入量的影响。这两项研究最初旨在比较低碳水化合物（LC）与低脂（LF）饮食，或由大部分最少加工食品（MPF）或超加工食品（UPF）组成的宏量营养素匹配饮食的受试者体内能量摄入差异。
对20名随机分配为先食用LC饮食后立即食用LF饮食（LC→LF）或相反顺序（LF→LC）的成年人以及20名随机分配为先食用MPF饮食后食用UPF饮食（MPF→UPF）或相反顺序（UPF→MPF）的成年人，在四周内评估饮食顺序组之间体重、身体成分变化、能量消耗差异和食物摄入量。
随机分配到LC→LF组的受试者比LF→LC组多减轻2.9±1.1千克体重（P<0.001）和1.5±0.6千克体脂（P=0.03），这可能是因为LC→LF组比LF→LC组每天少摄入922±304千卡热量（P=0.0024）。LC→LF组相对于LF→LC组能量摄入减少是在最后两周出现的（-1610±306千卡/天；P<0.00001），这可能是由于前两周肠道适应性的残留效应，这两周食物量（1295±209克/天；P<0.00001）和纤维摄入量（58±5克/天；P<0.00001）差异很大。在UPF→MPF组和MPF→UPF组之间，饮食顺序对能量摄入、体重或身体成分变化没有影响。
在一项为期4周的住院患者交叉饮食研究中，饮食顺序会影响每日能量摄入、体重变化和脂肪变化，该研究中宏量营养素不同，但加工程度和目的相同。
美国国立卫生研究院国立糖尿病、消化和肾脏疾病研究所内部研究项目。
NCT03407053和NCT03878108。
