{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,29]],"date-time":"2026-01-29T12:39:36Z","timestamp":1769690376740,"version":"3.49.0"},"reference-count":39,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2018,11,18]],"date-time":"2018-11-18T00:00:00Z","timestamp":1542499200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nutrients"],"abstract":"<jats:p>In phenylketonuria (PKU), synthetic protein derived from L-amino acids (AAs) is essential in a low-phenylalanine (Phe) diet. Glycomacropeptide (GMP), an intact protein, is very low in Phe in its native form. It has been modified and adapted for PKU to provide an alternative protein source through supplementation with rate-limiting amino acids (GMP-AAs), although it still contains residual Phe. This review aims to systematically evaluate published intervention studies on the use of GMP-AAs in PKU by considering its impact on blood Phe control (primary aim) and changes in tyrosine control, nutritional biomarkers, and patient acceptability or palatability (secondary aims). Four electronic databases were searched for articles published from 2007 to June 2018. Of the 274 studies identified, only eight were included. Bias risk was assessed and a quality appraisal of the body of evidence was completed. A meta-analysis was performed with two studies with adequate comparable methodology which showed no differences between GMP-AAs and AAs for any of the interventions analysed. This work underlines the scarcity and nature of studies with GMP-AAs interventions. All were short-term with small sample sizes. There is a need for better-designed studies to provide the best evidence-based recommendations.<\/jats:p>","DOI":"10.3390\/nu10111794","type":"journal-article","created":{"date-parts":[[2018,11,21]],"date-time":"2018-11-21T11:23:27Z","timestamp":1542799407000},"page":"1794","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":42,"title":["The Use of Glycomacropeptide in Patients with Phenylketonuria: A Systematic Review and Meta-Analysis"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9138-6556","authenticated-orcid":false,"given":"Maria Jo\u00e3o","family":"Pena","sequence":"first","affiliation":[{"name":"Departamento de Biomedicina, Unidade de Bioqu\u00edmica, Faculdade de Medicina, Universidade do Porto, 4200-319 Porto, Portugal"}]},{"given":"Alex","family":"Pinto","sequence":"additional","affiliation":[{"name":"Department of Dietetics, Birmingham Children\u2019s Hospital, Birmingham B4 6NH, UK"},{"name":"Faculty of Health &amp; Human Sciences, University of Plymouth, Plymouth PL6 8BH, UK"}]},{"given":"Anne","family":"Daly","sequence":"additional","affiliation":[{"name":"Department of Dietetics, Birmingham Children\u2019s Hospital, Birmingham B4 6NH, UK"}]},{"given":"Anita","family":"MacDonald","sequence":"additional","affiliation":[{"name":"Department of Dietetics, Birmingham Children\u2019s Hospital, Birmingham B4 6NH, UK"}]},{"given":"Lu\u00eds","family":"Azevedo","sequence":"additional","affiliation":[{"name":"Faculdade de Medicina, Universidade do Porto, 4200-319 Porto, Portugal"},{"name":"Department of Community Medicine, Information and Health Decision Sciences (MEDCIDS), 4200-450 Porto, Portugal"},{"name":"Center for Health Technology and Services Research (CINTESIS), 4200-450 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4977-8345","authenticated-orcid":false,"given":"J\u00falio C\u00e9sar","family":"Rocha","sequence":"additional","affiliation":[{"name":"Center for Health Technology and Services Research (CINTESIS), 4200-450 Porto, Portugal"},{"name":"Centro de Gen\u00e9tica M\u00e9dica Dr Jacinto de Magalh\u00e3es, Centro Hospitalar Universit\u00e1rio do Porto, 4099-028 Porto, Portugal"},{"name":"Centro de Refer\u00eancia na \u00e1rea das Doen\u00e7as Heredit\u00e1rias do Metabolismo, Centro Hospitalar Universit\u00e1rio do Porto\u2014CHP EPE, 4099-001 Porto, Portugal"}]},{"given":"Nuno","family":"Borges","sequence":"additional","affiliation":[{"name":"Center for Health Technology and Services Research (CINTESIS), 4200-450 Porto, Portugal"},{"name":"Faculdade de Ci\u00eancias da Nutri\u00e7\u00e3o e Alimenta\u00e7\u00e3o, Universidade do Porto, 4200-465 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2018,11,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1417","DOI":"10.1016\/S0140-6736(10)60961-0","article-title":"Phenylketonuria","volume":"376","author":"Blau","year":"2010","journal-title":"Lancet"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"812","DOI":"10.1016\/S0140-6736(53)90473-5","article-title":"Preliminary communication","volume":"262","author":"Bickel","year":"1953","journal-title":"Lancet"},{"key":"ref_3","first-page":"1","article-title":"The complete European guidelines on phenylketonuria: Diagnosis and treatment","volume":"12","author":"MacDonald","year":"2017","journal-title":"Orphanet J. 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