Higgins Kelly A, Rawal Rita, Kramer Matthew, Baer David J, Yerke Aaron, Klurfeld David M
United States Department of Agriculture (USDA), Agricultural Research Service, Beltsville Human Nutrition Research Center, Beltsville, MD, United States; Exponent Inc., Chemical Regulatory & Food Safety, Washington, DC, United States.
United States Department of Agriculture (USDA), Agricultural Research Service, Beltsville Human Nutrition Research Center, Beltsville, MD, United States.
Adv Nutr. 2024 Dec;15(12):100239. doi: 10.1016/j.advnut.2024.100239. Epub 2024 Aug 8.
Numerous systematic reviews (SR) and meta-analyses (MA) on low calorie sweeteners (LCS) have been published in recent years, concluding that LCS have beneficial, neutral, or detrimental effects on various health outcomes, depending on the review.
The objective of this overview of reviews was to determine how the methodologies of SR investigating the association between LCS consumption and body weight (BW) influence their findings and whether MA results can provide a consistent estimated effect.
Systematic searches of PubMed, Scopus, and Cochrane Library were conducted in November 2022 to identify SR of randomized controlled trials (RCT) or non-randomized studies (NRS) investigating the association between LCS consumption and BW. The methods, MA results, and conclusions were extracted from each eligible SR.
Of the 985 search results, 20 SR evaluated the association between LCS and BW, drawing from publications of 75 RCT, 42 prospective cohort studies, and 10 cross-sectional studies. There was a considerable lack of overlap of studies included within each SR attributed, in part, to the inclusion of studies based on design; thus, each SR synthesized results from distinctly different studies. Evidence synthesis methods were heterogeneous and often opaque, making it difficult to determine why results from certain studies were excluded or why disparate results were observed between SR.
SR investigating the effect of LCS on BW implement different methodologies to answer allegedly the same question, drawing from a different set of heterogeneous studies, ignoring the basic assumptions required for MA, resulting in disparate results and conclusions. Previous MA show the large effects of study design, which results in inconsistent estimates of the effect of LCS on BW between MA of RCT and NRS. Given the availability of long-term RCT, these studies should be the basis of determining causal relationships (or lack thereof) between LCS and BW. This trial was registered at PROSPERO as CRD42022351200.
近年来，已发表了大量关于低热量甜味剂（LCS）的系统评价（SR）和荟萃分析（MA），结论是LCS对各种健康结局具有有益、中性或有害影响，具体取决于评价结果。
本综述性评价的目的是确定研究LCS消费与体重（BW）之间关联的SR方法如何影响其研究结果，以及MA结果是否能提供一致的估计效应。
2022年11月对PubMed、Scopus和Cochrane图书馆进行了系统检索，以识别研究LCS消费与BW之间关联的随机对照试验（RCT）或非随机研究（NRS）的SR。从每项符合条件的SR中提取方法、MA结果和结论。
在985条检索结果中，20项SR评估了LCS与BW之间的关联，这些研究来自75项RCT、42项前瞻性队列研究和10项横断面研究的出版物。每项SR中纳入的研究存在相当大的差异，部分原因是基于设计纳入研究；因此，每项SR综合了截然不同的研究结果。证据综合方法各不相同且往往不透明，难以确定为何某些研究结果被排除，或为何不同SR之间观察到不同结果。
研究LCS对BW影响的SR采用不同方法来回答所谓相同的问题，这些方法基于不同的异质性研究，忽视了MA所需的基本假设，导致结果和结论不同。先前的MA显示了研究设计的巨大影响，这导致RCT和NRS的MA之间对LCS对BW影响的估计不一致。鉴于长期RCT的可用性，这些研究应作为确定LCS与BW之间因果关系（或不存在因果关系）的基础。本试验在PROSPERO注册为CRD42022351200。
