Hunger once seemed like a simple problem. Around the globe, often in low-income countries, many people didn’t get enough calories. But increasingly, hunger exists side-by-side with obesity. Within the same community, some people are overweight while others don’t have enough to eat. And the tricky part: You can’t “fix” hunger by just feeding people empty calories. You’ve got to nourish people with healthy, nutrient-dense foods, so they don’t become obese.

A new report published in The Lancet shines a spotlight on this paradox. The dual problems of undernourishment and obesity — often referred to as the double burden of malnutrition. For example, people can begin life not getting enough calories and become stunted — below average height for age — but by adulthood can become overweight due to an abundance of cheap calories.

Similarly, an obese teenager even in a wealthy country like the U.S. can easily grow overweight from eating junk food yet still be deficient in micronutrients that are key for optimal health. “The new nutrition reality is about countries having not just undernutrition or just having obesity but about … the combination of both,” says Corinna Hawkes, a report author, and director of the Centre for Food Policy at City, University of London.

The report finds an estimated 2.3 billion children and adults are overweight and more than 150 million children are stunted. The problem, researchers say, is that the ideal diet includes plenty of fruits and vegetables, whole grains and beans, but much of the globe has developed a taste for snack foods full of refined carbohydrates and sugar.

“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,” says report author Barry Popkin, a professor of nutrition at the University of North Carolina, Chapel Hill. “The new nutrition reality is driven by changes to the food system, which have increased availability of ultra-processed foods that are linked to increased weight gain.”

Popkin and his co-authors argue that systematic changes are needed to fix the problem: Everything from changing food production and processing to how foods are priced, labeled and marketed. “All relevant policies and investments must be radically re-examined,” says Francesco Branca, Director of the Department of Nutrition for Health and Development at the World Health Organization. And, given that poor diets are now linked to more deaths than smoking, there’s an urgency, researchers say. “We can no longer characterize countries as low-income and undernourished, or high-income and only concerned with obesity. All forms of malnutrition have a common denominator: food systems that fail to provide all people with healthy, safe, affordable and sustainable diets,” Branca says.

Read the rest of the article at NPR