Protein quality in ready-to-use supplementary foods for moderate wasting

Protein quality malnutrition

Protein quality refers to the evaluation of a food or a diet based on its amino acid composition, protein digestibility, and protein bioavailability. When these parameters are specified, either through direct measurement or estimation, the amino acids provided by the diet are compared to those required by a healthy individual, and based on this comparison, an adequacy ratio or score is assigned. Two widely used protein quality scoring systems are the protein digestibility-corrected amino acid score (PDCAAS) and the digestible indispensable amino acid score (DIAAS), neither of which account for the dietary source of the protein. In malnourished children, metabolic adaptations reduce the endogenous availability of amino acids and increase the demand for protein synthesis. These increased amino acid requirements are primarily driven by the presence of acute infection and the need for tissue accretion. This review examines two large clinical feeding trials involving moderately malnourished children, where dietary protein quality was carefully measured. The finding s suggest that protein quality scores alone do not reliably predict weight gain or recovery in these children and that consuming milk protein provides distinct advantages over vegetable-based proteins.

Digestible indispensable amino acid score (DIAAS): 10 years on

The objective of the review is to revisit the findings of the 2011 Food and Agriculture Organization of the United Nations (FAO) Expert Consultation on Dietary Protein Quality Evaluation in Human Nutrition, and to report on progress on uptake of the findings. It is evident that since 2011 there has been a concerted research effort to enhance an understanding of the protein quality of foods. The validity of the growing pig ileal protein digestibility assay has been confirmed and numerous studies reported using the growing pig as a model to give true ileal amino acid digestibility values for foods as consumed by humans. This has allowed for the determination of digestible indispensable amino acid scores (DIAAS) for a range of foods. A new non-invasive true ileal amino acid digestibility assay in humans which can be applied in different physiological states, called the dual-isotope assay, has been developed and applied to determine the DIAAS values of foods. It is concluded that DIAAS is currently the most accurate score for routinely assessing the protein quality rating of single source proteins. In the future, the accuracy of DIAAS can be enhanced by improved information on: the ideal dietary amino acid balance including the ideal dispensable to indispensable amino acid ratio; dietary indispensable amino acid requirements; effects of processing on ileal amino acid digestibility and lysine bioavailability. There is a need to develop rapid, inexpensive in vitro digestibility assays. Conceptual issues relating DIAAS to food regulatory claims, and to holistic indices of food nutritional and health status are discussed. The first recommendation of the 2011 Consultation regarding treating each indispensable amino acid as an individual nutrient has received little attention. Consideration should be given to providing food label information on the digestible contents of specific indispensable amino acids.

Effectiveness of Dietary Management for Moderate Wasting among Children > 6 Months of Age-A Systematic Review and Meta-Analysis Exploring Different Types, Quantities, and Durations

Currently, no World Health Organization guidelines exist for the management of approximately 31.8 million moderately wasted children globally. The objective of this review was to synthesise evidence on the optimal type, quantity, and duration of dietary treatment for moderate wasting. Ten electronic databases were searched until the 23rd of August 2021. Experimental studies comparing interventions for the dietary management of moderate wasting were included. Meta-analyses were conducted and results were presented as risk ratios or mean differences with 95% confidence intervals. Seventeen studies comparing specially formulated foods were included involving 23,005 participants. Findings suggest little or no difference in recovery between Fortified Blended Foods (FBFs) with improved micronutrient and/or milk content (enhanced FBFs) and lipid-based nutrient supplements (LNS), whereas children treated with non-enhanced FBFs (locally produced FBFs or standard corn-soy blend) may have lower recovery rates than those treated with LNS. There was no difference in recovery when ready-to-use therapeutic and ready-to-use supplementary food were compared. Other outcomes mostly aligned with results for recovery. In conclusion, LNSs improve recovery compared to non-enhanced FBFs, but are comparable to enhanced FBFs. Programmatic choice of supplement should consider factors such as cost, cost-effectiveness, and acceptability. Further research is required to determine optimal dosing and duration of supplementation.

Supplementary Feeding of Moderately Wasted Children in Sierra Leone Reduces Severe Acute Malnutrition and Death When Compared to Nutrition Counseling: a Retrospective Cohort Study

BACKGROUND

There is uncertainty about whether children with moderate wasting should receive supplementary feeding.

OBJECTIVES

We examined whether supplementary feeding compared to counseling alone in children with moderate wasting prevented progression to severe acute malnutrition (SAM) or death.

METHODS

This was a retrospective, dual cohort study in which 1,791 children with moderate wasting were drawn from two prior randomized controlled trials that took place in the same location in rural Sierra Leone. 1,077 children received supplementary feeding, while 714 children received counseling alone. Children in both cohorts were followed for at least 24 weeks from enrollment. The primary outcome was time to SAM or death using Kaplan-Meier analysis. Secondary outcomes included time to death as well as proportions of children with healthy mid-upper arm circumference (MUAC), moderate wasting, SAM, or death at 6, 12, and 24 weeks from enrollment.

RESULTS

Children who received supplementary feeding were less likely to develop SAM or die across the entire follow-up period (HR 0.53, 95% CI 0.44, 0.65, P < 0.001). Time to event for death alone also revealed a lower risk for children who received supplementary feeding (HR 0.52, 95% CI 0.28, 0.94, P = 0.03). Children who received supplementary feeding were more likely to have a healthy MUAC at 6 weeks (RR 2.0, 95% CI 1.7, 2.2) and 12 weeks (RR 1.3, 95% CI 1.2, 1.5), were less likely to develop SAM at 6 (RR 0.7, 95% CI 0.6, 0.9), 12 (RR 0.5, 95% CI 0.3, 0.8), and 24 weeks (RR 0.2, 95% CI 0.1, 0.5), and had higher rates of gain in weight and MUAC at 6 and 12 weeks.

CONCLUSIONS

Supplementary feeding of children with moderate wasting reduces risk of SAM and death across 24 weeks of follow-up.

Protein quality in ready-to-use supplementary foods for moderate wasting

There are no guidelines for the optimal protein quality of ready-to-supplementary food (RUSF) for moderate acute malnutrition (MAM). This randomized, controlled, double-blinded, clinical effectiveness trial evaluated two RUSFs in the treatment of MAM. Both foods contained greater than 7% dairy protein, but the protein-optimized RUSF had a calculated digestible indispensable amino acid score (DIAAS) of 95%, whereas the control RUSF had a calculated DIAAS of 63%. There were 1,737 rural Malawian children 6-59 months of age treated with 75 kcal/kg/day of either control or protein quality-optimized RUSF for up to 12 weeks. There was no difference in the proportion of children who recovered from MAM between the group that received protein-optimized RUSF (759/860, 88%) and the group that received control RUSF (766/877, 87%, difference 1%, 95% CI, -2.1 to 4.1, p = 0.61). There were no differences in time to recovery or average weight gain; nor were adverse effects reported. Both RUSFs showed indistinguishable clinical outcomes, with recovery rates higher than typically seen in treatment for MAM. The DIAAS of these two RUSFs was measured using a pig model. Unexpectedly, the protein quality of the optimized RUSF was inferior to the control RUSF: DIAAS = 82% for the protein quality optimized RUSF and 96% for control RUSF. The controlled conditions of this trial suggest that in supplementary food products for MAM, protein quality is not an independent predictor of clinical effectiveness.