A systematic review and meta-analysis of sex differences in undernutrition

View this article as a pdf

Research snapshot¹

Despite considerable research into childhood sex differences in neonatal and infant health, different disciplines tend to hold surprisingly contrary views and findings on the relative vulnerability of male and female children. Sex differences within nutrition programmes have not been explored in detail but there is a commonly held belief that girls are more vulnerable to undernutrition from a gender perspective. This paper explores the evidence on male/female differences in undernutrition in children under five years of age.

Seventy-four studies were identified with measures of male/female wasting, stunting and underweight prevalence estimates and 44 were included in the meta-analysis. In the 20 studies that examined wasting, 17 (85%) found that wasting was more prevalent in boys than girls, with boys having a higher odds ratio (OR) of being wasted (pooled OR 1.26, 95% CI 1.13 to 1.40). In the 38 studies that examined stunting, 32 (85%) studies showed stunting to be more prevalent in boys than girls with a higher pooled OR of 1.29 (95% CI 1.22 to 1.37). In the 23 studies exploring underweight, 18 (78.2%) studies indicated that underweight was more prevalent in boys than girls with a pooled OR of 1.14 (95% CI 1.02 to 1.26).

When analysed by region, the odds of being malnourished were nearly always higher for boys than for girls for all three manifestations of undernutrition although there was some evidence that female advantage, in terms of lower risk of stunting and underweight, was weaker in South Asia than other regions. When analysed by age, the odds of boys being wasted, stunted or underweight were higher than girls in all age categories.  

Forty-three studies (58%) offered potential explanations for the differences although the reasons provided tended to be varied and often conjectural. Six studies noted biological factors (including immune and endocrine differences), 21 studies noted social reasons (including gender dynamics and preferential feeding practices) and 16 studies noted a combination of the two. The findings suggest that sex differences in undernutrition should be further explored in research, policy and programming.

Subscribe freely to receive Field Exchange content to your mailbox or front door.