Background <p>COPD patients suffering from malnutrition or sarcopenia often incur higher healthcare costs and experience adverse clinical outcomes. Despite this, the effectiveness of nutrient supplements in this population remains uncertain.</p> Methods and analysis <p>Two reviewers will independently search seven databases—PubMed, Embase, Web of Science, China National Knowledge Infrastructure, Wanfang, Chinese Biomedical Literature Database, and the Cochrane Library—for randomized controlled trials (RCTs) published before August 31, 2024. These RCTs should compare the effects of nutrient supplements against either a standard diet or placebo supplements in patients with COPD. The risk of bias in the included studies will be evaluated using the modified Jadad scale and the Cochrane Collaboration's risk of bias tool. Data synthesis will be conducted using RevMan software. Trial sequential analysis (TSA) will be applied to the primary outcomes. Additionally, subgroup and sensitivity analyses will be performed to assess the robustness of the findings.</p> Ethics and dissemination <p>Ethical approval is not required because this study is a secondary analysis of existing data. We will disseminate the findings through peer- reviewed publications.</p> Systematic review registration <p>CRD42024585694.</p> Strengths and limitations of this study <p>This systematic review and meta-analysis provides a thorough assessment of the efficacy of nutrient supplements in COPD patients, covering a wide range of studies.</p> <p>·The use of the modified Jadad scale and the Cochrane Collaboration's risk of bias tool ensures a robust evaluation of study quality. Additionally, trial sequential analysis and subgroup analyses are employed to enhance the robustness of the findings.</p> <p>·The credibility of the evidence may be compromised due to the potential for uncertain study quality and limited sample sizes in some included trials.</p>