Prevalence of protein, lysine, and tryptophan inadequacy and their relation to stunting among Malawian under five children: evidence from the 2019/20 Integrated Household Survey.

BACKGROUND

Despite Malawi facing a high burden of multiple nutrient deficiencies arising mostly from low dietary supplies, nutrition assessments focus largely on micronutrients (e.g., minerals and vitamins), ignoring macronutrients such as protein. This study aimed to assess prevalence of inadequate dietary intake of protein and two essential amino acids lysine and tryptophan and their relation to stunting among Malawian under five children.

METHODS

We extracted data on household food consumption, expenditure and anthropometry for 5,952 children aged 6-59 months from the 2019/20 Malawi's Fifth Integrated Household Survey. Household food consumption and expenditure data were processed in R Studio with outliers replaced using median values, edible portions derived using conversion factors and all data standardized using Adult Female Equivalent (AFE). Relevant Food Composition Tables and database were utilized to estimate apparent intake of total and available protein, lysine, and tryptophan. Nutrient adequacy was assessed using the cut-off method based on Estimated Average Requirements, applying FAO thresholds. Anthropometric data were used to assess stunting, calculated using Z-scores in accordance with the 2006 WHO Growth Standards.

RESULTS

Respectively, inadequate available protein, lysine and tryptophan were prevalent in 49.0%, 56.4% and 25.7% of the children. Stunted children faced worse deficits - 52.5% inadequate available protein vs. 47.2% in non-stunted children (p < 0.001). Inadequate available lysine intake (61.5%) was most evident in the Central region, available protein inadequacy was higher in rural (50.7%) than urban areas (39.2%) (p < 0.001), whereas available tryptophan gaps were significantly greater (p = 0.009) in female- (28.7%) than male-headed households (24.6%).

CONCLUSION

Inadequate intake of protein, lysine, and tryptophan was prevalent among children, particularly among those who were stunted and those living in rural areas. Regional variations were evident, with lysine inadequacy most pronounced in the Central region, while tryptophan inadequacy was more prevalent in female-headed households.