People living in Indian states with high levels of income inequality experience a greater risk of both under- and overnutrition, according to research from the Harvard School of Public Health (HSPH) and the University of Bristol.

The researchers found that for every three per cent widening in a state’s income inequality between the most affluent and the most poor, the risk for being underweight increased by 19 per cent and the risk for being obese increased by 21 per cent.

“Put simply, here's one macro-economic determinant that affects the health of the poor, via making them undernourished, and the rich, via making them overnourished, simultaneously,” said lead author S V Subramanian, associate professor in the HSPH Department of Society, Human Development, and Health.

The researchers analysed a nationally representative database of 77,220 Indian women between the ages of 15 and 49 years, using body mass index as an indicator of under- and overnutrition.  The women lived in 26 states in India.  Income inequalities among the states were measured by differences in per capita consumption.

In an additional finding, higher per capita consumption expenditure at the state-level, which is a marker of economic development, was associated with an increased risk of obesity.  Yet, no association was observed between higher state per capita consumption expenditure and reduced risk for undernutrition, suggesting that economic development does not have a guaranteed connection to alleviating disease among the impoverished, noted Professor Subramanian.

The authors suggest that economic inequality and the resulting increased risk for under- and overnutrition does not reflect a lack or overabundance of resources.  Rather, they emphasize the role of the distribution of these resources.

“Arguably, states with a high level of income inequality tend to not only facilitate opportunities for over-consumption, but may also lead to system-level inefficiencies and corruption that in turn fail to provide adequate nutrition for those who need it,” asserted Professor Subramanian.

To address this double-disease burden and to optimise health outcomes, the authors propose implementing strategies such as ensuring access to adequately nutritional food by the poor and disseminating information about the adverse impacts of obesity within the general population and especially among the affluent.

Income inequality and the double burden of under- and overnutrition in India, S V Subramanian, Ichiro Kawachi, and George Davey Smith. Journal of Epidemiology and Community Health, 2007;61;802-809.