Household food insecurity (HFI) is a major concern in South Asia. The pathways by which HFI may reduce child growth remain inadequately understood. In a cohort study of 12 693 maternal–infant dyads in rural Bangladesh, we examined association and likely explanatory pathways linking HFI, assessed using a validated nine-item perception-based index, to infant size at 6 months. Mothers were assessed early in pregnancy for anthropometric status, dietary diversity and socio-economic status. Infants were assessed for weight, length, and arm, chest and head circumferences and breast and complementary feeding status at birth and 6 months of age. Extent of HFI shared a negative, dose–response association with all measures of infant size at 6 months and odds of wasting and stunting; 57–89 % of variances in the unadjusted models were explained by prenatal factors (maternal nutritional status and dietary diversity), and birth size adjusted for gestational age. Postnatal infant breast and complementary feeding and morbidity exposures explained the remaining fraction of the significant association between HFI and differences in infant arm and chest circumferences and odds of underweight. Contextual (i.e. socio-economic) factors finally brought remaining non-significant fractions of the food insecurity-related mid-infancy growth deficit to practically zero. Improving food security prior to pregnancy and during gestation would likely improve infant growth the most in rural Bangladesh.

Environmental enteric dysfunction (EED) and systemic inflammation (SI) are common in developing countries and may cause stunting. In Bangladesh, >40 % of preschool children are stunted, but EED and SI contributions are unknown. We aimed to determine the impact of EED and SI (assessed with multiple indicators) on growth in children (n 539) enrolled in a community-based randomised food supplementation trial in rural Bangladesh. EED was defined with faecal myeloperoxidase, α-1 antitrypsin and neopterin and serum endotoxin core antibody and glucagon-like peptide-2, consolidated into gut inflammation (GI) and permeability (GP) scores, and urinary lactulose:mannitol α-1 acid glycoprotein (AGP) characterised SI. Biomarker associations with anthropometry (15-, 18- and 24-month length-for-age (LAZ), weight-for-length (WLZ) and weight-for-age (WAZ) z scores) were examined in pairwise correlations and adjusted mixed-effects regressions. Stunting, wasting and underweight prevalence at 18 months were 45, 15 and 37 %, respectively, with elevated EED and SI markers common. EED and SI were not associated with 15–24-month length trajectory. Elevated (worse) GI and GP scores predicted reduced 18–24-month WLZ change (β −0·01 (se 0·00) z score/month for both). Elevated GP was also associated with reduced 15–18-month WLZ change (β −0·03 (se 0·01) z score/month) and greater 15-month WLZ (β 0·16 (se 0·05)). Higher AGP was associated with reduced prior and increased subsequent WLZ change (β −0·04 (se 0·01) and β 0·02 (se 0·00) z score/month for 15–18 and 18–24 months). The hypothesised link from EED to stunting was not observed in this sample of Bangladeshi 18-month-olds, but the effects of EED on constrained weight gain may have consequences for later linear growth or for other health and development outcomes.

Asian populations have a higher percentage body fat (%BF) and are at higher risk for CVD and related complications at a given BMI compared with those of European descent. We explored whether %BF was disproportionately elevated in rural Bangladeshi women with low BMI. Height, weight, mid-upper arm circumference, triceps and subscapular skinfolds and bioelectrical impedance analysis (BIA) were measured in 1555 women at 3 months postpartum. %BF was assessed by skinfolds and by BIA. BMI was calculated in adults and BMI Z-scores were calculated for females <20 years old. Receiver operating characteristic (ROC) curves found the BMI and BMI Z-score cut-offs that optimally classified women as having moderately excessive adipose tissue (defined as >30 % body fat). Linear regressions estimated the association between BMI and BMI Z-score (among adolescents) and %BF. Mean BMI was 19·2 (sd 2·2) kg/m2, and mean %BF was calculated as 23·7 (sd 4·8) % by skinfolds and 23·3 (sd 4·9) % by BIA. ROC analyses indicated that a BMI value of approximately 21 kg/m2 optimised sensitivity (83·6 %) and specificity (84·2 %) for classifying subjects with >30 % body fat according to BIA among adults. This BMI level is substantially lower than the WHO recommended standard cut-off point of BMI ≥ 25 kg/m2. The equivalent cut-off among adolescents was a BMI Z-score of –0·36, with a sensitivity of 81·3 % and specificity of 80·9 %. These findings suggest that Bangladeshi women exhibit excess adipose tissue at substantially lower BMI compared with non-South Asian populations. This is important for the identification and prevention of obesity-related metabolic diseases.

Equations for predicting body composition from bioelectrical impedance analysis (BIA) parameters are age-, sex- and population-specific. Currently there are no equations applicable to women of reproductive age in rural South Asia. Hence, we developed equations for estimating total body water (TBW), fat-free mass (FFM) and fat mass in rural Bangladeshi women using BIA, with 2H2O dilution as the criterion method. Women of reproductive age, participating in a community-based placebo-controlled trial of vitamin A or β-carotene supplementation, were enrolled at 19·7 (sd 9·3) weeks postpartum in a study to measure body composition by 2H2O dilution and impedance at 50 kHz using multi-frequency BIA (n 147), and resistance at 50 kHz using single-frequency BIA (n 82). TBW (kg) by 2H2O dilution was used to derive prediction equations for body composition from BIA measures. The prediction equation was applied to resistance measures obtained at 13 weeks postpartum in a larger population of postpartum women (n 1020). TBW, FFM and fat were 22·6 (sd 2·7), 30·9 (sd 3·7) and 10·2 (sd 3·8) kg by 2H2O dilution. Height2/impedance or height2/resistance and weight provided the best estimate of TBW, with adjusted R2 0·78 and 0·76, and with paired absolute differences in TBW of 0·02 (sd 1·33) and 0·00 (sd 1·28) kg, respectively, between BIA and 2H2O. In the larger sample, values for TBW, FFM and fat were 23·8, 32·5 and 10·3 kg, respectively. BIA can be an important tool for assessing body composition in women of reproductive age in rural South Asia where poor maternal nutrition is common.

The association of early postnatal growth with diseases in adults such as hypertension, type 2 diabetes and CHD has generated interest in studying postnatal growth. Bioelectrical impedance analysis (BIA) is a useful measure to estimate total body water (TBW) and fat-free mass (FFM). We evaluated three published equations (Fjeld et al. (Pediatr Res (1990) 27, 98–102), Bocage (MSc Thesis (1988) University of West Indies) and Kushner et al. (Am J Clin Nutr (1992) 56, 835–839) to measure TBW and derived FFM based on BIA, using 2H2O dilution as a reference method for suitability in infants in India. In a cross-sectional study in seventy-eight apparently healthy infants aged 6–24 months from the urban poor attending an immunisation clinic at a hospital in Kolkata, we measured their length to the nearest 0·1 cm, weight to the nearest 10 g, resistance at 50 kHz using BIA and TBW using 2H2O dilution. TBW was derived using three published BIA-based equations and compared with TBW using 2H2O dilution. Based on the BIA equations of Fjeld et al., Bocage and Kushner et al., the mean TBW values were 2·46 % (P < 0·001), 4·62 % (P < 0·001) and 9·50 % (P < 0·001) lower than the reference 2H2O method, respectively. All three published BIA-based equations consistently underestimated the TBW and FFM and appeared inadequate for studying infants in India. The equation described by Fjeld et al. gave the smallest deviation from the reference method and may be used for field studies. New equations based on population-specific data are desirable for a more precise measure of TBW.

Rapid postnatal growth in low-birth weight infants increases the risk of hypertension, CHD and type 2 diabetes in adult life. To provide validated tools to study the growth in South Asian infants, we evaluated two published equations to measure total body water (TBW) and fat-free mass (FFM) based on anthropometry in 6- to 24-month-old infants, using 2H2O dilution. In a method-comparison study in seventy-eight infants aged 6–24 months (forty-two girls and thirty-six boys) from the urban poor attending an immunisation clinic of a hospital in Kolkata, we measured their length to the nearest 0·1 cm, weight to the nearest 10 g and TBW using 2H2O dilution. The calculated TBW in kg (TBWkg) and FFM in kg (FFMkg) using two equations based on the length and weight were each compared with TBWkg and FFMkg calculated from 2H2O dilution. The mean FFMkg were 7·31 (sd 1·11), 7·13 (sd 1·08) and 7·26 (sd 1·13) by the 2H2O dilution method, and the anthropometry equations of Mellits and Cheek (AN-1) and Morgenstern et al. (AN-2), respectively. The mean of the paired difference in FFMkg was 0·18 (sem 0·06) and 0·04 (sem 0·07) between 2H2O, and AN-1 and AN-2, respectively. There is a good agreement for FFM derived by AN-2 with 2H2O dilution. The former is 1 % lower than that obtained from the reference method (P = 0·28). The AN-2 equation is useful for evaluating FFM in infants in India.

We evaluated the adverse effect of asymptomatic Helicobacter pylori infection in children on the response to Fe supplementation. One hundred and sixty-nine children aged 1–10 years from the urban poor community underwent a [13C]urea breath test for H. pylori and haematological tests at admission and after 8 weeks. Both H. pylori-positive and -negative children were randomly assigned to receive ferrous fumarate syrup (20 mg elemental Fe twice daily) or placebo for 8 weeks and a single dose of vitamin A (33,000μg). Admission findings were compared between H. pylori-positive and -negative children. Response to Fe was compared between Fe-supplemented H. pylori-positive and -negative children. Seventy-nine per cent of the children were aged 1–5 years and half of them were boys. In eighty-five H. pylori-positive and eighty-four H. pylori-negative children, the differences in mean Hb (112 (sd 12·6) v. 113 (sd 12·0) g/l), haematocrit (34 (sd 3·5) v. 35 (sd 3·2) %) and ferritin (23·8 v. 21·0 μg/l) were similar. After 8 weeks of Fe supplementation, mean Hb was 5·3 g/l more (95 % CI 1·59, 9·0) and haematocrit was 1·4 % more (95 % CI 0·2, 2·6) in H. pylori-negative (n 44) compared with H. pylori-positive (n 42) children. Mean ferritin was similar at admission and improved in both H. pylori-positive and -negative children. Asymptomatic H. pylori infection was not associated with higher rates of anaemia or Fe deficiency in children, but had a significant adverse effect on response to Fe therapy. However, this result is based on exploratory analysis and needs confirmation.