The association between different types of amino acid intake and physical growth among children

Restricted linear growth and abnormal weight status are commonly observed among children in low-income countries, possibly due to inadequate protein intake. Considering the role of protein intake and amino acid (AA) synthesis in growth and development, it has been suggested that there may be an association between AA intake and physical growth. We aimed to investigate the association between different types of AA intake and physical growth among children.

A cross-sectional study including 780 six-year-old children referred to 10 health care centers for vaccination between October 2017 and March 2018 was conducted. Anthropometric data was collected using standard methods, and dietary intake was assessed using a validated food-frequency questionnaire (FFQ)‏ in an interview by a trained technician.

Children in the highest tertile (3rd) of branched-chain amino acids (BCAA) intake had a higher weight-for-age z-score (WAZ) (P = 0.02) and body mass index-for-age z-score (BAZ) (P = 0.001) compared to those in the lowest tertile (1st). Interestingly, BAZ was significantly associated with the highest tertile of acidic AA intake (P = 0.04), while an inverse association was observed between the highest tertile of aromatic AA (phenylalanine and tyrosine) intake and BAZ (P = 0.01) . No significant associations were observed between the highest tertile of sulfuric, aliphatic, or neutral AA and BAZ, height-for-age z-score (HAZ) or WAZ. Further, underweight was associated with the 3rd tertile of aromatic, alcoholic, aliphatic or neutral AA and BCAA intake. Aliphatic and neutral AA intake was also increased the risk of overweight. Finally, stunted growth patterns were associated with the highest tertile of acidic, alcoholic.

Findings presented in this study showed that higher BAZ and WAZ are associated with 3rd tertiles of BCAA intake, but lower BAZ were associated with 3rd tertiles of aromatic AA (phenylalanine and tyrosine) intake. Future research in other populations are needed to confirm these findings.