Oct. 22, 2007 -- The obesity epidemic is actually a worldwide pandemic that has global implications for health and disease, new research shows.
In one of the largest studies ever to examine obesity rates across the globe, researchers found that more than 60% of men and 50% of women were either overweight or obese.
They concluded that obesity is a growing problem in all regions of the world, even among traditionally lean Asian populations.
"The study shows that excess body weight is pandemic, with one-half to two-thirds of the overall study population being overweight or obese," researcher Beverley Balkau, PhD, of the French health service INSERM, says in a news release.
The study involved 69,409 men and 98,750 women from 63 countries across five continents evaluated by their primary care doctors for body weight, height, cardiovascular disease (heart disease or stroke), diabetes, and waist circumference. The U.S. was not included in the study.
Waist circumference is now considered an important marker of obesity-related diseases such as heart disease and diabetes. A waist circumference of more than 40 inches in men and 35 inches in women is considered a risk factor for these diseases.
The people in the study had visited their doctor on one of two specially designated days in which detailed information on weight, height, waist circumference, and disease history were collected for the trial, providing a snapshot of the prevalence of obesity worldwide.
Body mass index (BMI) was calculated from the weight and height measurements. BMI looks at a person's weight in relation to height and is used to determine obesity and overweight. Forty percent of men and 30% of women met the criteria for being overweight, meaning they had a BMI of 25 to 29.9.
Fully a quarter of men and women met the BMI definition of obese (BMI of 30 or greater), but obesity rates did differ by region, ranging from a low of 7% among men and women living in southern and eastern Asian countries to a high of 36% among men and women living in Canada.
Just under one in three men and almost half of the women had waist circumferences of more than 40 and 35, respectively, putting them at higher risk for heart disease and diabetes.
The rate of diagnosed heart disease among male and female study participants was 16% and 13%, respectively. A total of 13% of men and 11% of women had known diabetes.
The men and women in the study with the largest waists were more than twice as likely as those with the smallest waists to have heart disease.
Diabetes risk was three times higher for the quarter of men with the biggest waists and almost six times higher for women, compared with the quarter of the study population with the smallest waists.
The study is published in the latest issue of the American Heart Association (AHA) journal Circulation.
Reversing the Obesity Trend
While people living in southern and eastern Asia fared better than other populations in terms of obesity and waist circumference, the researchers point out that this is not necessarily reassuring because their rates of obesity are also rising.
American Heart Association spokesman Gerald Fletcher, MD, of the Jacksonville branch of the Mayo Clinic, tells WebMD that the study provides important confirmation of the global reach of obesity.
"We have known that obesity is a worldwide problem, but this is the largest study yet to actually show this," he says.
Balkau and colleagues conclude that unless the trend is reversed, the rise in obesity will result in major increases in sickness and death from related diseases like diabetes.
Fletcher agrees, adding that major public health initiatives are needed to address the problem.
"We have seen that such initiatives can work to reduce cigarette smoking," he says. “We have to have the same kind of commitment to make a difference in obesity rates."