874 digital scale

Anthropometric measurements were collected monthly and included length (Infant/Child ShorrBoard^®; Weigh and Measure, LLC; http://www.weighandmeasure.com/), weight (Seca 874 digital scale; http://www.seca.com/en_mw/products/all-products/product-details/seca874.html), MUAC (Child MUAC Tape; Weigh and Measure, LLC), subscapular and triceps skinfolds (Holtain T/W skinfold caliper; http://www.holtain.com/tw.php) and head and chest circumference. The digital scales were tested weekly for accuracy using standard weights. Motor development assessments were conducted using the WHO motor development skills framework⁽²⁹ (link)⁾.

Height and weight were measured by portable measuring instruments for all participants (Seca 874 digital scale for weight [in kilograms] and Seca 213 stadiometer for height [in centimeters], Seca). Body mass index (BMI) was calculated as weight in kilograms divided by heights in meters squared. For the main analysis, obesity was defined as a BMI of 30 or greater according to World Health Organization classification for the general population.²⁵ For sensitivity analysis, we used other BMI cutoffs^{26 (link)} (27.5 and 25) considered for Asian populations and alternative anthropometric measures²⁷ (waist circumference and waist-to-hip ratio).

For demonstrating the application of this score, we used data from the fifth round of the National Family Health Survey (NFHS-5, 2019-21). The NFHS-5 is a household survey conducted in 2019-21, covering all the States and Union Territories of India. This survey is designed to generate estimates of population, health, and nutrition at national, state/union territory (UT), and district levels. Four survey schedules (Household, Woman’s, Man’s, and Biomarker) were canvassed in 636,699 households across India using Computer Assisted Personal Interviewing (CAPI). The NFHS-5 has collected information of 724,115 women (15–49 years), 101,839 men (15–54 years), and 232,920 children (0–59 months). The height and weight of children (0–59 months) were measured and recorded in the NFHS-5. The weight of children (0–59 months) was measured using the Seca 874 digital scale. The height of children (24–59 months) was measured with the Seca 213 stadiometer. The Seca 417 Infantometer was used to measure the recumbent length of children under two years or less than 85 cm. The WHO Z-scores for HAZ (height-for-age), WHZ (weight-for-height), and WAZ (weight-for-age) were also available in the data set.

The Demographic and Health Surveys (DHS) are nationally and regionally representative household-based surveys of women aged 15–49 years, individually conducted in various countries [14 , 15 ]. During sampling, countries were divided into survey regions, which are sub-national units that correspond to existing administrative units such as states or provinces. These sub-national units were stratified by urban and rural areas and cluster sampling was carried out in two stages. First, from each region, urban/rural stratified random sampling of enumeration units or clusters were conducted. Next, within each enumeration unit, a random sample of households was selected for inclusion in the survey. Information such as household sociodemographic status and women’s reproductive history were self-reported. Trained personnel collected anthropometric data by measuring and recording participants’ weight using the SECA 874 digital scale to the nearest 0.01 kg and height with the Shorr height board. These anthropometric measurements were recorded in the biomarker questionnaire [16 ]. Detailed description of the survey methodology and administration is published elsewhere [14 ]. We were only able to access 34 SSA country datasets from the DHS database and these were identified for potential inclusion in the study analysis.

The outcome of interest, the nutritional status of women, was assessed by the Body Mass Index (BMI). In NFHS-5, anthropometric measurements of all participating women were taken by the trained health investigators. The height of women was measured using the Seca 213 Stadiometer and the weight using the Seca 874 Digital Scale. The BMI was calculated using the standard formula [weight/height² (kg/m²)] and was classified following WHO recommended cut-off: <18.5 kg/m2 (underweight), 18.5–24.9 kg/m2 (normal) and ≥ 25.0 kg/m2 (overweight) [30 ].

The anthropometric measurements of length, weight, and head circumference, collected at 24 months of age, were used in this analysis. Child length was measured to the nearest 0.1 cm using height–length ShorrBoard^® stadiometers. Weight was measured to the nearest 0.1 kg using Seca 874 digital scales. The child’s head circumference was measured to the nearest 0.1 cm using standard pediatric circumference bands. Three measurements were taken for each parameter and an average value was computed. The 2006 World Health Organization (WHO) growth standards were used to calculate anthropometric z-scores [34 ]. Children with length-for-age z-score (LAZ) between −2 and −3 were classified as moderately stunted and with LAZ below −3 were severely stunted. Similarly, children with weight-for-length z-score (WLZ) between −2 and −3 were classified as moderately wasted and below −3 as severely wasted. Similarly, children with head circumference-for-age z-score (HCZ) between −2 and −3 were classified as having moderate microcephaly and below −3 as having severe microcephaly. In accordance with WHO standards, one case with a LAZ outlier (i.e., LAZ < −6) was excluded in this analysis [34 ].