Understanding Sex Differences in Childhood Undernutrition: A Narrative Review

Abstract

Complementing a recent systematic review and meta-analysis which showed that boys are more likely to be wasted, stunted, and underweight than girls, we conducted a narrative review to explore which early life mechanisms might underlie these sex differences. We addressed different themes, including maternal and newborn characteristics, immunology and endocrinology, evolutionary biology, care practices, and anthropometric indices to explore potential sources of sex differences in child undernutrition. Our review found that the evidence on why sex differences occur is limited but that a complex interaction of social, environmental, and genetic factors likely underlies these differences throughout the life cycle. Despite their bigger size at birth and during infancy, in conditions of food deprivation, boys experience more undernutrition from as early as the foetal period. Differences appear to be more pronounced in more severe presentations of undernutrition and in more socioeconomically deprived contexts. Boys are more vulnerable to infectious disease, and differing immune and endocrine systems appear to explain some of this disadvantage. Limited evidence also suggests that different sociological factors and care practices might exert influence and have the potential to exacerbate or reverse observed differences. Further research is needed to better understand sex differences in undernutrition and the implications of these for child outcomes and prevention and treatment programming.

Prevalence and Determinants of Undernutrition among Under-Five Children in Nigeria: A Systematic Review

“…Stunting was found to be higher in males in two studies in this review and this is similar to the findings by Thurstans et al, (2022) and also by Amare, Ahmed and Mehari (2019). Genetic, social and environmental factors are said to be responsible for this (Thurstans et al, 2022). One of the most important predictors of stunting is birth order (Rahman, 2016).…”

“…Also, at this age children start to feed themselves more and this may contribute to insufficient intake of protein and energy (Rahman, 2016). Stunting was found to be higher in males in two studies in this review and this is similar to the findings by Thurstans et al, (2022) and also by Amare, Ahmed and Mehari (2019). Genetic, social and environmental factors are said to be responsible for this (Thurstans et al, 2022).…”

Childhood BMI and other measures of body composition as a predictor of cardiometabolic non-communicable diseases in adulthood: a systematic review

“…Sex differences also matter and should be explored in future work. Not enough papers presented disaggregated data for us to comment on sex-specific differences in this review but differences are well recognised for the risks of both early-life malnutrition (81,82) and adult NCDs (83) . Thus we hope that future researchers would carefully account for sex when documenting any links between early body composition and later life NCD.…”

Anthropometric deficits and the associated risk of death by age and sex in children aged 6–59 months: A meta‐analysis

“…Research has also demonstrated sex differences in undernutrition whereby boys are often more likely to be wasted, stunted and underweight than girls (Costa et al, 2021 ; Garenne et al, 2019 ; Khara et al, 2018 ; Myatt et al, 2018 ; Thurstans et al, 2020 ). Evidence on the reasons for these differences is limited, and to date, the possible implications for treatment and mortality outcomes have not been well researched (Thurstans et al, 2022 ).…”