Tier 4 — mechanistic

Low serum glycine strengthens the association between branched-chain amino acids and impaired insulin sensitivity assessed before and after weight loss in a population with pre-diabetes: The PREVIEW_NZ cohort

Lim JJ, Prodhan UK, Silvestre MP, Liu AY, McLay J, Fogelholm M, Raben A, Poppitt SD, Cameron-Smith D
Clinical nutrition (Edinburgh, Scotland) 2024 43(12):17-25

Bibliography

PubMed
PMID 39423758
DOI
10.1016/j.clnu.2024.09.047
Trial registry
View on ClinicalTrials.gov Registered trial — results not yet published in a peer-reviewed journal.
Funding
Indexed support: Health Research Council of New Zealand; European Commission Seventh Framework Programme for Research and Technological Development. See the publication for grant and funder details.
Competing interests
The accessible abstract does not establish the authors' competing interests; absence of a statement is not evidence of no conflicts.

Study snapshot

DesignHuman observational study
ModelAdult humans
Sample167 paired samples from adults with prediabetes who achieved at least 8% weight loss
InterventionSecondary analysis of an 8-week low-energy diet; measured glycine and BCAA, without glycine supplementation
Duration8 weeks
EndpointsGlycine and BCAA concentrations; Insulin-sensitivity-related markers

What the study showed, in plain terms

This PREVIEW subcohort analysis found that low glycine strengthened the association between BCAA and impaired insulin sensitivity. It examines a metabolic signature during weight loss, not glycine supplementation.

Key findings

  • The analysis used paired baseline and postdiet samples.
  • Joint consideration of glycine and BCAA was informative for insulin-sensitivity associations.

What this study can and cannot tell us

Selected successful weight-loss participants limit generalizability.

Associations within a diet study do not show that glycine supplementation prevents diabetes.

Related papers in the corpus

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The metabolic response to ingested glycine
Gannon MC et al. · The American journal of clinical nutrition · 2002
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Effect of glycine on insulin secretion and action in healthy first-degree relatives of type 2 diabetes mellitus patients
González-Ortiz M et al. · Hormone and metabolic research = Hormon- und Stoffwechselforschung = Hormones et metabolisme · 2001
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Glycine treatment decreases proinflammatory cytokines and increases interferon-gamma in patients with type 2 diabetes
Cruz M et al. · Journal of endocrinological investigation · 2008
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Oral supplementation with glycine reduces oxidative stress in patients with metabolic syndrome, improving their systolic blood pressure
Díaz-Flores M et al. · Canadian journal of physiology and pharmacology · 2013
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Metabolic impact of dietary glycine supplementation in individuals with severe obesity
Tan HC et al. · Scientific reports · 2025
Tier 4
De Novo Glycine Synthesis Is Reduced in Adults With Morbid Obesity and Increases Following Bariatric Surgery
Tan HC et al. · Frontiers in endocrinology · 2022

Editorial review

Reviewed by the Biohack Blueprint research team

Last verified

Dr. Khaled Mahmoud, MBBChCritical Care Medicine, Longevity Science & Editorial Direction