(Natural News) Obesity has become a global epidemic, affecting more than 650 million people. Poor diet is one of the reasons behind this widespread problem. A study published in The British Medical Journal found that oversized meals served at restaurants and fast food outlets are part of a poor diet, and associated with obesity.

In the study, researchers weighed and measured the energy content of 223 popular meals served by 111 randomly selected sit-down restaurants and fast food outlets in Brazil, China, Finland, Ghana, and India.

The researchers found that 94 percent of the most popular main dishes served in sit-down restaurants and 72 percent of those purchased over the counter from fast food outlets contain more than 600 kilocalories (kcal) – the benchmark recommended by the National Health Service (NHS) in the U.K. to help reduce the global obesity epidemic. In particular, the researchers found that these meals provide between 70 percent and 120 percent of the daily energy needed by a sedentary woman – about 2,000 kcal – in most countries around the world except China. The energy content of the most popular meals in that country is significantly lower.

Vivian Suen, a professor at the University of Sao Paulo's Ribeirao Preto Medical School and a coauthor of the study, said that these findings suggest people are not only eating the wrong kinds of foods, they are overeating them.

"And in terms of calories, a meal considered healthy may often increase the organism's energy balance and hence add more weight than a fast food meal," Suen added.