The temporal pattern of early adiposity in Indian babies
Indian babies are thought to have relatively more fat mass for a given body size compared to other ethnicities, but we do not know whether this extra accretion begins during foetal life (appearing at birth), or occurs during postnatal life, particularly when catch-up growth occurs in small babies.
South Asian children and adults have been observed to have more fat mass (FM) for a given Body Mass Index (BMI) compared to Caucasians (1), with a greater propensity compared to other ethnic groups, for developing non-communicable diseases like type 2 diabetes, even at a normal BMI. This relative adiposity was thought to begin during foetal growth, due to adverse circumstances in utero, or as a result of intergenerational effects, in a process called foetal programming. This hypothesis was based on a study that showed that Indian babies appeared to have preserved subscapular skinfold thickness at birth with lower birth weights, in comparison with babies born in the UK (2). This finding of excess adiposity at birth suggested that adverse environmental conditions in utero could affect long-term health through early and permanent effects on body composition, growth and metabolism. While this shone a welcome light on the need for an adequate nutritional status in pregnancy, this finding was not replicated in later Indian studies, including by us, where babies, at birth, were found to have normal skinfolds or FM by accurate measurements like deuterium dilution, whole body potassium measurements or air displacement plethysmography (3-5). However, there is still no doubt that older Indian children and adults are relatively more adipose than other ethnicities. Therefore, the focus has shifted towards the role of accelerated growth in the early postnatal period contributing to a greater FM accretion. In our previous study (3) on a cohort of Indian babies born in New Delhi, we have reported that in term babies, the FM was already showing signs of greater accretion when growth was rapid in the first 12 days of postnatal life. This shows that the early measurement of FM is important, we do not know how this high FM accretion propagates through later infant life.
What did we find out?
In our manuscript (6) entitled “Body composition from birth to 2 years in term healthy Indian infants measured by deuterium dilution: Effect of being born small for gestational age and early catch-up growth”, we follow up the term children whose FM we described at birth (3) and now describe the change in FM in their first 2 years of life. The mean birthweight of the cohort of 144 babies that we had measured at birth was 2863±418g (3), and we were able to follow up and document their FM at 3.5mo, 1y and 2y. Thus, in 144, 166, 81 and 115 babies at 12d, 3.5mo, 1y and 2y respectively, the FM, as a proportion of body weight, was11.6, 21.1, 17.9 and 22.4% respectively. The FM was measured accurately at all these time points by the deuterium dilution method, and also standardized for length as the Fat Mass Index (FMI, FM (kg)/length (m)2).
There was no difference in FMI between boys and girls at all ages. Babies who demonstrated catch-up growth between 0-2y had higher FMI at 2 y compared to those who did not. It is worth noting that the babies in the present study had a lower FM% and FMI until they were 1y of age compared to reports for babies from other countries. However, the present Indian babies showed an increase in adiposity between 1 to 2y, whereas in other country studies, the FM% remained stable or even declined between 1 and 2y of age. This unique temporality in the accretion of FM in Indian babies, who are born with normal FM, suggests a different biology representing an early adiposity rebound, with important implications for the feeding of these children. Further longitudinal body compositional measurement in Indian children, as well as those of other ethnicities, particularly when born with low birth weight, will clarify whether the early accelerated growth pattern contributes to greater accrual of fat rather than lean mass during childhood.
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- Radha Krishna KV, Hemalatha R, Mamidi RS, Geddam BJJ, Balakrishna N. Do South Indian newborn babies have higher fat percentage for a given birth weight? Early Hum Dev. 2016;96:39-43.
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- Jain V, Kumar B, Devi S, Jain A, Jana M, Kurpad AV. Body composition from birth to 2 years in term healthy Indian infants measured by deuterium dilution: Effect of being born small for gestational age and early catch-up growth. Eur J Clin Nutr. 2022. (In Press)