ARI SHAPIRO, HOST:
There are now more obese people in the world than people who are underweight, according to a study published in the medical journal The Lancet. Dr. James Bentham is one of the authors of the study and joins us now.
Welcome to the show.
JAMES BENTHAM: Thank you. Thank you for having me.
SHAPIRO: How did you reach this conclusion?
BENTHAM: So we have collected data from 1,700 studies that have been carried out on height and weight around the world over the past 40 years. And we've pulled these data, which cover 186 countries, developed a statistical model of the data, and we found that this is the case that there are now more obese people than underweight people in the world.
SHAPIRO: And what led to this shift?
BENTHAM: So there are a whole host of reasons why this has happened. We've seen communicable disease prevalence reduced. This has meant that people are living to be older. People's diet has changed so people are eating more food that's high in fat, that's processed, that's sugary. And also we've seen a change in working practices. So people are doing far more sedentary occupations than they would've been doing in the past.
SHAPIRO: And so it sounds like it's not just an increase in obesity. It is an increase in obesity combined with an overall decrease in being undernourished.
BENTHAM: Yes. So what we've seen is that the prevalence of people who are underweight, clinically underweight, has reduced over this period and has now been overtaken by the prevalence of obesity. On the other hand, we still see that there is high prevalence of underweight in countries in South Asia in particular - so in India and Bangladesh. And also parts of Africa.
SHAPIRO: So you're talking about big regional differences when you look at the globe.
BENTHAM: There are big regional differences. The world seems to be divided roughly in two. So you have the high-income world and middle-income countries where we see this problem with obesity. And then in poorer countries, we see this dual burden so people are both underweight, but also increasingly wealthier people there are obese.
SHAPIRO: What percentage of people in the world are obese and what percentage of people in the world are underweight?
BENTHAM: So the percentage of people who are underweight is about 9 percent of people. The percentage of people who are obese is around 12 percent or 13 percent.
SHAPIRO: And you also found a gender divide.
BENTHAM: So what we see is that in most countries, women on average have higher BMI than men. The main exceptions from this are the high-income countries - so countries like the U.S. and the U.K., where male BMI is higher than female BMI.
SHAPIRO: What do your findings mean for public policy?
BENTHAM: We don't want to dictate to government. This a global study, and each country will need to develop its own solutions. But what we'd like to see is that governments could give people the opportunity to have healthy lifestyles. So for example, subsidies for fresh fruits and vegetables have been tried in various countries. It's possible to tax unhealthy foods, sugars, trans-trans fats and so on, and to provide public health programs and to provide more opportunities for physical activity.
SHAPIRO: How surprised were you by these conclusions?
BENTHAM: I think we always knew that there was a problem with obesity around the world. However, I think we're shocked by the level of obesity and also when we project into the future and see that perhaps if current trends continue, we may see 4 out of 10 adults in the world being obese within nine years.
SHAPIRO: That's Dr. James Bentham, a researcher at the School of Public Health at Imperial College, London, and one of the authors of the new study on obesity published in the medical journal The Lancet.
Thanks a lot.
BENTHAM: OK, thank you. Transcript provided by NPR, Copyright NPR.