Reporting on the study published April 2 in The Lancet, the BBC said the number of obese people had risen from 105 million in 1975 to 641 million in 2014, creating a global "crisis point," according to lead researcher Majid Ezzati, a professor in the School of Public Health at Imperial College London.
If trends continue, a fifth of the world's population will be obese by 2025, researchers said.
"Global obesity prevalence will reach 18 percent in men and surpass 21 percent in women; severe obesity will surpass 6 percent in men and 9 percent in women. Nonetheless, underweight remains prevalent in the world's poorest regions, especially in south Asia," the report said.
The World Health Organization blames increased consumption of high-fat, energy-dense foods, coupled with inactivity caused by modern lifestyles, for the rise in obesity.