W. Zhu, Q. Chen, D. Li and Y. Li (2026). Low-carbohydrate, high-fat diet is inversely associated with the triglyceride-glucose index: evidence from NHANES 1999-2018. European journal of medical research. https://doi.org/10.1186/s40001-026-04126-0

PubMed 41782055

[Abstract]
BACKGROUND: The association of the triglyceride-glucose index, a validated marker of insulin resistance, with specific dietary patterns is unclear.

METHODS: This cross-sectional analysis of NHANES 1999-2018 included 19,016 adults. Logistic regression, restricted cubic splines, and interaction analyses were used to evaluate associations between macronutrient intake and the triglyceride-glucose index. This analysis was designed a priori to evaluate whether a low-carbohydrate, high-fat macronutrient distribution (captured by PEC, PEF, and carbohydrate-to-fat energy ratio) is associated with the TyG index.

RESULTS: Higher quartiles of percentage energy from carbohydrates and carbohydrate-to-fat energy ratio were associated with higher odds of an elevated TyG index, whereas higher quartiles of percentage energy from fat were associated with lower odds. Restricted cubic splines showed a positive linear association for carbohydrate energy and an inverse linear association for fat energy with TyG. Interaction analyses supported that a low-carbohydrate, high-fat pattern correlated with lower fasting triglyceride levels, and mediation analysis indicated that fasting triglycerides explained ~ 49% of the association between carbohydrate-to-fat energy ratio and TyG.

CONCLUSIONS: A low-carbohydrate, high-fat diet was significantly associated with a lower triglyceride-glucose index; this association was primarily mediated by reductions in fasting triglyceride levels.