Researchers have claimed that there has been a startling increase in rates of obesity and overweight in both adults (28 per cent increase) and children (up by 47 per cent) in the past 33 years, with the number of overweight and obese people rising from 857 million in 1980 to 2.1 billion in 2013.

However, the rates vary widely throughout the world with more than half of the world's 671 million obese individuals living in just ten countries-the USA (more than 13 per cent), China and India (15 per cent combined), Russia, Brazil, Mexico, Egypt, Germany , Pakistan, and Indonesia, and (listed in order of number of obese individuals).

Over the past three decades, the highest rises in obesity levels among women have been in Egypt, Saudi Arabia, Oman, Honduras and Bahrain, and among men in New Zealand, Bahrain, Kuwait, Saudi Arabia, and the USA.

In high-income countries, some of the highest increases in adult obesity prevalence have been in the USA (where roughly a third of the adult population are obese), Australia (where 28 per cent of men and 30 per cent of women are obese), and the UK (where around a quarter of the adult population are obese).

The findings come from a comprehensive new analysis of the global, regional, and national prevalence of overweight and obesity in adults aged 20 years and older and children and adolescents aged 2-19 years between 1980 and 2013.

Led by Professor Emmanuela Gakidou from the Institute for Health Metrics and Evaluation at the University of Washington in the USA, a team of international researchers performed a comprehensive search of the available data from surveys, reports, and the scientific literature to track trends in the prevalence of overweight (body mass index of 25kg/m2 or higher) and obesity (BMI of 30kg/m2 or higher) in 188 countries in all 21 regions of the world from 1980 to 2013.

The study finding also revealed that in the developed world, men have higher rates of obesity than women, while the opposite is true in developing countries. Currently, 62 per cent of the world's obese people live in developing countries.

The greatest gain in overweight and obesity occurred globally between 1992 and 2002, mainly among people aged between 20 and 40.

The study has been published in journal The Lancet.