Obesity used to be largely an American pastime. No more. Getting fat is now a big global competition.

Reuters reports today: “Obesity levels in China are rising fast, with more than a quarter of the adult population overweight or obese, as people add more meat and dairy products to their diet, causing serious health problems.”

Other studies have found similar rising rates of obesity in other countries in recent years. The World Health Org now calls obesity a global epidemic. It seems everyone’s trying to get in on our game.

“Increased consumption of more energy-dense, nutrient-poor foods with high levels of sugar and saturated fats, combined with reduced physical activity, have led to obesity rates that have risen three-fold or more since 1980 in some areas of North America, the United Kingdom, Eastern Europe, the Middle East, the Pacific Islands, Australasia and China.The obesity epidemic is not restricted to industrialized societies; this increase is often faster in developing countries than in the developed world.”

As here, people in China don’t have to work as hard as they used to (that’s a gross averaging of the masses, of course) and so cancer and heart disease are on the rise, too. Delightful progress, eh?

“What’s happening in China should be seen as a marker for what is going to hit the rest of the developing world if we fail to act,” said researcher Barry Popkin of the University of North Carolina.

Also out today, a comprehensive study of studies that finds good diet and exercise promote healthier brains.

So why doesn’t everyone eat better? I guess a) we don’t have to, and b) it’s easy not to, and c) for some it’s very challenging culturally and economically, and d) our species is not really all that smart (see “promote healthier brains” above for tips on how to improve in this area).

And before the hate mail starts, this is not about aesthetics. Obesity kills friends, spouses, grandparents and children, and it is expensive for a society as it fuels diabetes and other diseases that we all pay for in skyrocketing health care costs. It makes us less competitive at work and less able-bodied as a nation. Poor diet choices are costing modern humans a fortune in body repair bills, pain and agony, and reduced years of life (the last few of which tend to be less enjoyable than they would be otherwise).

Slightly less seriously, some even argue that if everyone trimmed down a little, we’d save gas as our vehicles toted lighter loads. Clearly at the personal level, eating less would allow household budgets to draw in a notch. And for anyone planning to be a grandparent some day: Scientists now know that if you eat fewer calories (simply substitute veggies for a daily desert), you will likely have more time to bounce those grandkids on your knee.

Okay, none of that matters to you? Then it’s about sex.