摘要目的:系统检索、评价和整合中年肥胖糖尿病前期人群营养干预的循证医学文献。方法:基于参与者、干预措施、比较、结果和研究设计（Population，Intervention，Comparison，Outcomes and Study Design/Setting，PICOS）框架，计算机检索PubMed、Cochrane Library、Embase、Web of Science、中国知网、维普、万方等中英文数据库2019年1月1日至2023年12月31日的相关文献。纳入标准为36～59岁、体重指数（body mass index，BMI）≥28 kg/m2的糖尿病前期人群，研究类型限定为指南、专家共识、系统评价及随机对照试验（randomized controlled trial，RCT）。由两名研究者独立进行文献筛选、数据提取，并采用AGREE Ⅱ、AMSTAR 2、RoB 2.0等多维度工具评价文献质量。通过乔安娜·布里格斯研究所证据分级、GRADE系统及德尔菲法专家论证形成推荐意见，并对部分RCT数据进行了Meta分析。结果:最终纳入33篇文献，提炼出6个维度14条证据，包括间歇性禁食干预（3条）、进餐时间干预（3条）、进餐顺序调整（2条）、膳食模式干预（4条）、代餐治疗（1条）、差异化营养干预（1条）。结论:中年肥胖糖尿病前期人群需建立分级分类精准干预框架：优先推荐地中海饮食联合限时进食（Ⅰa级证据），动态监测骨骼肌质量变化（Ⅲb级证据）；需通过多中心、长周期临床试验验证代餐治疗（Ⅱb级证据）及低碳水饮食的长期效果；需结合地域代谢特征差异，开发适应性干预工具。

abstractsObjective:To systematically search, evaluate, and synthesize evidence-based medical literature on nutritional interventions for middle-aged obese individuals with prediabetes.Methods:Based on the Population, Intervention, Comparison, Outcomes, and Study Setting Disign/(PICOS) framework, a computerized search was conducted across seven Chinese and English databases and professional websites, including PubMed, Cochrane Library, Embase, Web of Science, CNKI, CQVIP, and Wanfang Data, for relevant literature published from January 1, 2019, to December 31, 2023. The inclusion criteria were for pre-diabetic populations aged 36-59 with a body mass index (BMI)≥28 kg/m2, and the study types were limited to guidelines, expert consensus, systematic reviews, and randomized controlled trials (RCTs). Two researchers independently performed literature screening and data extraction, and assessed the quality of the literature using multi-dimensional tools such as AGREE II, AMSTAR 2, and RoB 2.0. Recommendations were formulated through the Joanna Briggs Institute (JBI) evidence grading, the GRADE system, and expert consensus via the Delphi method, and a Meta-analysis was performed on data from some of the RCTs.Results:Finally 33 studies were included, from which 14 pieces of evidence were extracted from 6 dimensions, including intermittent fasting intervention (3 items), meal timing intervention (3 items), meal sequence adjustment (2 items), dietary pattern intervention (4 items), meal replacement therapy (1 item), and differentiated nutrition intervention (1 item).Conclusions:A tiered, categorized precision intervention framework for middle-aged obese prediabetic individuals requires: a primary recommendation of a Mediterranean diet combined with time-restricted eating (Level Ⅰa evidence) with skeletal muscle mass monitoring (Level Ⅲb); a call for multi-center, long-term trials to validate meal replacement (Level Ⅱb) and low-carbohydrate diet efficacy; and the development of adaptive tools that incorporate regional metabolic differences.