Associations between Stunting, Wasting and Body Composition: A Longitudinal Study in 6- to 15-Month-Old Kenyan Children.

BACKGROUND: Early growth and body composition may influence the risk of obesity and health in adulthood. Few studies have examined how undernutrition is associated with body composition in early life. OBJECTIVES: We assessed stunting and wasting as correlates of body composition in young Kenyan children. METHODS: Nested in a randomized controlled nutrition trial, this longitudinal study assessed fat and fat-free mass (FM, FFM) using deuterium dilution technique among children at age 6 and 15 months. This trial was registered at http://controlled-trials.com/ (ISRCTN30012997). Cross-sectional and longitudinal associations between z-score categories of length-for-age (LAZ) or weight-for-length (WLZ) and FM, FFM, fat mass index (FMI), fat-free mass index (FFMI), triceps, and subscapular skinfolds were analyzed by linear mixed models. RESULTS: Among the 499 children enrolled, breastfeeding declined from 99% to 87%, stunting increased from 13% to 32%, and wasting remained at 2% to 3% between 6 and 15 mo. Compared with LAZ >0, stunted children had a 1.12 kg (95% CI: 0.88, 1.36; P < 0.001) lower FFM at 6 mo and increased to 1.59 kg (95% CI: 1.25, 1.94; P < 0.001) at 15 mo, corresponding to differences of 18% and 17%, respectively. When analyzing FFMI, the deficit in FFM tended to be less than proportional to children's height at 6 mo (P ≤ 0.060) but not at 15 mo (P > 0.40). Stunting was associated with 0.28 kg (95% CI: 0.09, 0.47; P = 0.004) lower FM at 6 mo. However, this association was not significant at 15 mo, and stunting was not associated with FMI at any time point. A lower WLZ was generally associated with lower FM, FFM, FMI, and FFMI at 6 and 15 mo. Differences in FFM, but not FM, increased with time, whereas FFMI differences did not change, and FMI differences generally decreased with time. CONCLUSIONS: Overall, low LAZ and WLZ among young Kenyan children were associated with reduced lean tissue, which may have long-term health consequences.

Effect of locally produced complementary foods on fat-free mass, linear growth, and iron status among Kenyan infants: A randomized controlled trial.

The impact of quality complementary food products on infant growth and body composition has not been adequately investigated. This study evaluated the effect on fat-free mass (FFM) accrual, linear growth, and iron status of locally produced complementary food products comparing to a standard product. In a randomized, double-blind trial, 499 infants at 6 months received nine monthly rations of (a) WinFood Classic (WFC) comprising germinated amaranth (71%), maize (10.4%), small fish (3%), and edible termites (10%); (b) WinFood Lite (WFL) comprising germinated amaranth (82.5%), maize (10.2%), and multimicronutrient premix; or (c) fortified corn-soy blend plus (CSB+). Primary outcomes were changes in FFM, length, and plasma ferritin and transferrin receptors (TfR). FFM was determined using deuterium dilution. Analysis was by intention to treat, based on available cases. Compared with CSB+, there were no differences in change from 6 to 15 months in FFM for WFC 0.0 kg (95% CI [-0.30, 0.29]) and WFL 0.03 kg (95% CI [-0.25, 0.32]) and length change for WFC -0.3 cm (95% CI [-0.9, 0.4]) and WFL -0.3 cm (95% CI [-0.9, 0.3]). TfR increased in WFC group 3.3 mg L-1 (95% CI [1.7, 4.9]) and WFL group 1.7 mg L-1 (95% CI [0.1, 3.4]) compared with CSB+. Compared with the increase in Hb in CSB+ group, there was a reduction in Hb in WFC of -0.9 g dl-1 (95% CI [-1.3, -0.5]) and a lower increase in WFL -0.4 g dl-1 (95% CI [-0.8, 0.0]). In conclusion, the tested WinFoods had the same effect on FFM and length as CSB+, whereas Hb and iron status decreased, suggesting inhibited iron bioavailability from the amaranth-based WinFoods.