J Acad Nutr Diet. 2016 Jun;116(6):968-83. doi: 10.1016/j.jand.2016.01.003. Epub 2016 Mar 3.
Higher protein intake has been implicated in weight management because of its appetitive properties. However, the effects of protein intake on appetitive sensations such as fullness have not been systematically assessed. Meta-analysis is a useful technique to evaluate evidence of an intervention's effect on testable outcomes, but it also has important limitations.
The primary aim of this study was to synthesize the available evidence on the effect of protein intake on fullness using a quantitative meta-analysis and a secondary directional analysis using the vote-counting procedure. A tertiary aim was to address limitations of meta-analyses as they pertain to findings from this meta-analysis.
We searched multiple databases for interventional studies that evaluated the effect of increased protein intake on fullness ratings. Inclusion criteria for both analyses were as follows: healthy human participants, preload studies that utilized intact dietary protein, delivery of protein load orally, and studies reporting fullness as an outcome. For the meta-analysis, an additional criterion was that the studies also needed to report 2- to 4-hour area under the curve value for fullness.
Five studies met all criteria for the meta-analysis. Twenty-eight studies met all criteria for the directional analysis. The meta-analysis indicated higher protein preloads have a greater effect on fullness than lower protein preloads (overall effect estimate: 2,435.74 mm.240 min, (95% CI 1,375.18 to 3,496.31 mm.240 min; P<0.0001). The directional analysis also revealed a positive effect on fullness with higher protein preloads (P<0.01). Many related scientifically rigorous studies were excluded from the analysis because analytical criteria required a narrowly focused research question.
The present analyses show that higher protein preloads increase fullness ratings more than lower protein preloads under tightly defined conditions. Extrapolation of findings to common conditions outside the specified criteria of this analysis must be made cautiously, as must speculation about the influence of fullness sensations on ingestive behavior, body weight, and various health outcomes.
较高的蛋白质摄入量因其开胃特性而与体重管理有关。然而，蛋白质摄入量对饱腹感等食欲感觉的影响尚未得到系统评估。元分析是评估干预措施对可测试结果影响的有用技术，但它也有重要的局限性。
本研究的主要目的是使用定量元分析和使用投票计数程序的二次定向分析来综合关于蛋白质摄入量对饱腹感影响的现有证据。第三个目的是解决元分析的局限性，因为它们与本元分析的结果有关。
我们搜索了多个数据库，以寻找评估增加蛋白质摄入量对饱腹感评分影响的干预性研究。这两种分析的纳入标准如下：健康人类参与者、使用完整膳食蛋白质的预负荷研究、口服提供蛋白质负荷以及报告饱腹感作为结果的研究。对于元分析，还需要报告饱腹感的 2 至 4 小时曲线下面积值。
五项研究符合元分析的所有标准。二十八项研究符合定向分析的所有标准。元分析表明，较高的蛋白质预负荷对饱腹感的影响大于较低的蛋白质预负荷（总体效果估计：2435.74mm.240min，（95%CI 1375.18 至 3496.31mm.240min；P<0.0001）。定向分析也显示较高的蛋白质预负荷对饱腹感有积极影响（P<0.01）。许多相关的科学严谨研究因分析要求有一个针对性很强的研究问题而被排除在分析之外。
本分析表明，在严格定义的条件下，较高的蛋白质预负荷比较低的蛋白质预负荷更能增加饱腹感评分。必须谨慎地将研究结果外推到本分析规定标准之外的常见情况，并且必须推测饱腹感对摄食行为、体重和各种健康结果的影响。
