Several studies have shown that the average height of adults across the globe is on the rise, but against this trend, the average height of adults in India is declining at an alarming rate, as per a study titled ‘Trends of adult height in India from 1998 to 2015: Evidence from the National Family and Health Survey’.
“In the context of an overall increase in average heights worldwide, the decline in the average height of adults in India is alarming and demands an urgent inquiry. The argument for different standards of height for the Indian population as different genetic groups needs further scrutiny,” the authors of the study said.
However, the trends from India clearly underline the need to examine the non-genetic factors and also to understand the interplay of genetic, nutritional, and other social and environmental determinants on height, they added.
To trace the trends of height among adults in India, the authors conducted a quantitative secondary data analysis to explore the variation in height. The data on the height on a large scale is collected under the erstwhile National Nutritional Monitoring Bureau (NNMB) and the National Family Health Survey (NFHS).
In the 15-25 age group, the mean height of Indian women showed significant improvement between NFHS-II and NFHS-III. However, between NFHS-III and NFHS-IV, their average height declined by 0.12 cm. Between NFHS-III and IV, tribal women in the same age group showed a significant decline in their average height by 0.42 cm. The average height of women in the poorest wealth index category was observed to have suffered a significant decline.
The average height of Indian men in this age group has significantly declined by 1.10 cm between NFHS-III and IV. The decline in average height was observed across religious groups, caste or tribe, residence, and wealth index.
The state-wise trends of an average height of men in the 15-25 age group find only men from Nagaland showing significant improvement in their average height. Himachal Pradesh, Manipur, Meghalaya, and Mizoram also showed improvement in the average height of men while rest of the states exhibited a decline.