Indian men, women now taller but still fall short of optimal standards

Study suggests increase in optimal weight reflects height gain

Last month, a National Institute of Nutrition (NIN) report was headlined in the media as an increase in the “ideal” weight of Indians. The decadal report, titled “Nutrient Requirements for Indians 2020: Recommended Dietary Allowances & Estimated Average Requirements”, raised the “reference body weight” for men by 5 kg to 65 kg. But unlike what was widely reported, the reference weight for women has not been increased and remains 55 kg. In 2010, NIN had raised the reference weight for women by 5 kg to 55 kg.

What does it mean in layman terms?

A reference body weight represents what is optimal for age and sex of an apparently healthy representative population with favourable conditions for growth and development. Nutrient requirements of individuals depend on criteria such as age, gender, weight, height and physiological status (pregnancy, lactation and so on). The requirements are accordingly adjusted for body weight of different groups.

The report took into account anthropometric data for Indian adults from two datasets: The National Nutrition Monitoring Bureau (NNMB, 2015-16) and the National Family Health Survey (NFHS-4, 2015-16). From these, the 95th percentile of height was taken as it represents the full growth potential for adult male and female in the 19-39 age group.

The first recommendations on dietary intake of Indians – for an adult man of 55 kg and an adult woman of 45 kg – were made in 1944. In the last revised recommended dietary allowances (RDA) in 2010, the reference body weight of women was increased to 55 kg from 50 kg earlier, while retaining that of men at 60 kg.

Asked if the numbers suggest that Indians have grown taller since the 1940s, Hemalatha R, director of NIN, which is under the Indian Council of Medical Research, says “yes”. “This is attributable to a lot of factors like improved healthcare over the decades, food security, decrease in communicable diseases, better maternal nutrition et cetera.”

However, the increase in reference weight and height numbers need not offer much to celebrate for the vast majority, as they essentially mean that 95 per cent of the population still has to strive to attain these optimal standards.

A study by the Imperial College, London, found that since 1914, the average height of an Indian man grew by only 2.9 cm to 164.9 cm in 2014. Indian women, on the other hand, fared better as they added 4.9 cm to stand at 152.6 cm a century later.

Veena Shatrugna, former deputy director at NIN and a clinical nutritionist, says that the myth of genetics being the crucial determinant of a population's height has been busted. “The reason why people are underweight and short is because they have not got quality food during their growing years. And it takes at least three-four generations to reach the desirable average, which is an international average that everybody can reach,” she says.

It is a persuasive argument that is borne out by the case of the Netherlands, which is at the top of the table of the tallest. Natural selection, environmental conditions and nutrition — notably a surge in dairy consumption — are viewed as factors that transformed the Dutch into giants as they grew in height over 150 years since the middle of the 19th century.

As the average height of Indians has remained low, Shatrugna says, scientists could not rapidly increase the weight recommendations. “If you are short, and are told to increase weight, you could go on eating and only put on fat,” she says, adding that the new RDA report has raised the calcium requirements, which is welcome for ensuring better bone health.

When it comes to energy needs, Hemalatha points out that the basal metabolic rate (minimum calories required for basic functions while the body is at rest) of Indians is lower by 10-12 per cent compared to a Food and Agriculture Organisation/World Health Organisation/United Nations University formula. This has led to a lowering of calories.

The new RDA has also shifted to a newer protein quality index: Digestible indispensable amino acid score. “Therefore, what you see as a reduction in overall protein recommendation (42.9 gm per day for men, and 36.3 g/d for women) is actually one based on high-quality protein,” says the NIN director. Following the earlier method — protein digestibility-corrected amino acid score — the RDA in 2010 had proposed 60 g/d (men) and 55 g/d (women).

With good quality protein, every gram one eats gets absorbed, Shatrugna says. “It comes from animal sources. But if you take the protein from <dal> or soyabean, just about 60 per cent gets used up,” she says.

Given the current politics over food, with a focus on vegetarianism and marginalisation of some sections who consume meat, Shartugna says that the poor should not merely be provided with rations but also encouraged to consume meat, eggs, milk, vegetables and fruits to ensure a balanced diet and growth.

That can be a starting point to making the average Indian healthier and taller.