New York, Dec 16 (IANS): Low-and middle-income countries have high levels of overweight and obesity along with undernutrition, say researchers, adding that these two issues have become increasingly connected.

"Our research shows that overweight and obesity levels of at least 20 per cent among adults are found in all low-income countries. Furthermore, the double burden of high levels of both undernutrition and overweight occur primarily in the lowest-income countries -- a reality that is driven by the modern food system," said study lead author Barry M. Popkin from University of North Carolina in US.

"This system has a global reach and is preventing low- and even moderate-income countries and households from consuming safe, affordable and healthy diets in a sustainable way," Popkin added.

Globally, estimates suggest that almost 2.3 billion children and adults are overweight, and more than 150 million children are stunted.

In low- and middle-income countries, however, these emerging issues overlap in individuals, families and communities.

For the findings, the research team used survey data from low- and middle-income countries in the 1990s and 2010s to estimate which countries faced a double burden of malnutrition, meaning that, in the population, more than 15 per cent of people had wasting, more than 30 per cent were stunted, more than 20 per cent of women had thinness and more than 20 per cent of people were overweight.

The results, published in the journal The Lancet, showed that more than a third of low- and middle-income countries had overlapping forms of malnutrition, 45 of 123 countries in the 1990s and 48 of 126 countries in the 2010s.

The problem was particularly common in sub-Saharan Africa, south Asia, and east Asia and the Pacific, where 29, seven and nine countries were affected, respectively.

In the 2010s, 14 countries with some of the lowest incomes in the world had newly developed a double burden of malnutrition compared with the 1990s, said the study.

However, fewer low- and middle-income countries with the highest incomes, relative to others in that category, were affected.

The authors said this reflects the increasing prevalence of people being overweight in the poorest countries, even as segments of the population still face stunting, wasting and thinness.

"The poorest low- and middle-income countries are seeing a rapid transformation in the way people eat, drink and move at work, home, in transport and in leisure," Popkin said.

According to the researchers, the new nutrition reality is driven by changes to the food system, which have increased the global availability of ultra-processed foods that are linked to weight gain while also adversely affecting infant and preschooler diets.

"These changes include disappearing fresh food markets, increasing numbers of supermarkets, and the control of the food chain by supermarkets and global food, catering and agriculture companies in many countries," Popkin said.