Pleasantly plump, big-boned, rotund, meatier, beefed-up, and portly -- whatever your favorite term, the people of the world have grown much larger over the past thirty years, and not vertically.  In a massive trio of studies [abstract 1, abstract 2, abstract 3] in medicine's top peer-reviewed journal Lancet, the results are astounding -- obesity rates have doubled in less than 30 years.

It is the marvel of modern medicine -- even as the waists of world's citizens swell, cholesterol and heart disease rates are dropping thanks to daily-ingested pills.

Meanwhile, obesity rates have soared from 5 percent of men and 8 percent of women worldwide in 1980 to 10 percent for men and 14 percent for women by the study's end in 2008.  That means that as of two years ago a whopping 343 million men and 458 million women worldwide were of an unhealthy weight.  Another 1.5 billion adults -- roughly a quarter of the world's population, were overweight.

The figure used to measure obesity was the body-mass-index.  While BMI -- a height to weight ratio -- can be misleading in highly muscular individuals, in most cases it is one of the most accurate and quickest ways of assessing the amount of fat a person carries.

The study [press release], conducted by researchers from Harvard University, the Imperial College of London, and other top global universities, was the most comprehensive analysis of BMI, cholesterol, and blood pressure in the worldwide population, to date.

According to the report, Americans are by far the fattest of any developed nation.  Japanese, on the other hand, are the skinniest developed nation. (The most obese non-developed nation is American Samoa.)  But while the west is leading the way in the rise in obesity, obesity rates in Asia are also creeping up.

Majid Ezzati, a professor of public health at Imperial College London and one of the study's authors, comments in a CBS News interview, "Being obese is no longer just a Western problem."

As the fattest continue to get fatter, the experts warn of a coming "global tsunami of cardiovascular disease." Medicine, they say, can only do so much to stave off nature.  Sonia Anand [profile] and Salim Yusuf [profile] of McMaster University in Hamilton, Ontario authored an accompanying review [abstract] in Lancet, in which they state, "[The forecast for global heart disease is] dismal and comprises a population emergency that will cost tens of millions of preventable deaths [unless action is taken]."

Besides cardiovascular disease, obesity carries a host of other problems including an increased risk of a host of cancers, diabetes, digestive problems, and sexual impotence.  In other words, it's pretty much the mother of all diseases.

Besides the U.S., other regions growing fast in the waist are Latin America, the Middle East, and Western and Southern Africa.  Only regions like central Africa and South Asia bucked the global trend.

Researchers say there are a number of options on the cardiovascular disease front -- including mandating lower salt in manufactured foods and banning transfats.  Likewise new medications may be able to continue to counter the effects of the world's higher fat content.  

But the underlying problem is that people increasingly eating too much, and modern medicine has little answer to that issue.  When confronted with their unhealthy behaviors, many defiantly defend their right to overeat.

And the outlook for the other obesity diseases like cancer and diabetes is more dismal.  States Professor Ezzati [profile], "We don't know how much worse the obesity problem will get. While we can manage blood pressure and cholesterol with medication, diabetes will be a lot harder." 

The three studies' lead authors were Farshad Farzadfar [profile], Mariel M. Finucane [profile], and Goodarz Danaei [profile] -- all of which are researchers at Harvard University in various departments.