What is Body Mass Index (BMI)? Why Indian 19-year-olds’ BMI Rank Among Lowest at the Global level?

In a recent report of the international medical journal The Lancet conducted on the basis of Height and body-mass index trajectories of the school-aged children, India ranked third and fifth from the bottom respectively among countries where 19-year-old boys and girls have a low BMI. This study presents the first comparable estimates of height in school-aged children and adolescents for all countries in the world and does so alongside estimates of BMI, which together are pathways from nutrition and environment during childhood and adolescence to lifelong health.

What is Body Mass Index (BMI)? 

Body Mass Index (BMI) is a measurement of a person’s weight with respect to his or her height. It is more of an indicator than a direct measurement of a person’s total body fat. The WHO defines an adult who has a BMI between 25 and 29.9 as overweight - an adult who has a BMI of 30 or higher is considered obese - a BMI below 18.5 is considered underweight, and between 18.5 to 24.9 a healthy weight.

The Lancet Study on BMI and India’s Position at the Global Level

In 2019, The Lancet pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. The primary outcomes were population mean height and mean BMI from ages 5 to 19 years. 

This global analysis of data spanning 34 years from 200 countries ranked India at 196th place with respect to BMI (Body Mass Index). The normal ranges between 20 and 25. This study reveals that the 19-year-old boys and girls in India do not just have a poor BMI, but are also one of the shortest 19-year old population in the world.

The review published in the international medical journal ‘The Lancet’ states that India’s boys ranked 180th with an average height of 5.46 feet while girls ranked 182th with an average height of 5.06 feet 

Why do Indian 19-year-olds have low BMI?

Dr. A Laxmaiah, head of the Public Health Nutrition division at the National Institute of Nutrition, Hyderabad states “In developing countries like India, we have a dual burden i.e., overnutrition and undernutrition. The prevalence of overweight and obesity among adolescents of both Indian girls and boys is lower when compared to children of developed nations. The reasons could be several, like variations in the epigenetic, dietary intakes, familial, psychosocial, parental education, occupations, income, etc.” 

Way Forward

There is a need for regular diet and nutrition surveys in India to avert the reducing level of BMI among the young adult of the country. Malnutrition is one of the major reasons due to a liking for nutritionally-deficient fast foods in urban youth or due to poverty in rural areas. Active government intervention and welfare policies in rural areas can help the youth beat malnutrition and other stunted growth-related problems. In urban areas, awareness programs and health initiatives should be taken up by schools and colleges to guide the youth about a healthy lifestyle.