World's 7 billionth citizen is less likely to die from infectious diseases like measles or even AIDS, but more at risk of contracting diabetes or other non-communicable diseases (NCDs), as they are now the leading causes of deaths globally.
The pathological picture changes, as more than half the world's 7 billion people live in urban areas.
"Our new world citizen number 7 billion is more likely to grow up in an urban setting, which increases his or her risk of getting diabetes, as well as chronic obstructive pulmonary disease (COPD), cancer and heart disease," said Siri Tellier, from the Copenhagen School of Global Health at the University of Copenhagen.
World citizen number 7 billion, who was estimated to be born on 31 October, will face very different diseases than that of children born only a few decades ago.
As the population of urban areas keeps growing, it rapidly changes the global health challenges.
"Until 2008, the majority of the world population lived in rural areas, but since then the majority has become urban, and most future population growth will happen in urban areas of developing countries. And one third of them, a little more than one billion, live in urban slums," stated Siri Tellier.
In the cities of the world, the health challenge is twofold: Firstly, living conditions in slum areas are poor, both with respect to water and sanitation, and access to health care almost non existent.
In addition, life in urban areas often entails a shift toward 'modern' life styles, with inadequate nutrition, especially more fatty, salty foods, smoking, alcohol and lack of exercise - all primers for NCDs.
Young adults in the big cities of the world are more likely to eat fattier, salty foods, smoke and drink alcohol than their parents left behind in rural areas.
Secondly, when the young newcomers become parents, their own poor health will have influenced the unborn child's predisposition for NCDs.
"Our new world citizen no. 7 billion will probably grow up in an urban setting, and will face factors that increase his or her risk of diabetes, as well as COPD, cancer and heart disease," Tellier added.