There’s no doubt that Americans are bigger today than they were in the 1960s. But Christopher Ingraham at the Washington Post pulled out some staggering stats to demonstrate exactly how big Americans have become: the average woman today weighs 166.2 pounds — which is almost the exact same amount as the average American man in the early 1960s.

Both sexes have gotten bigger since over the past 50 years. Men are 17.6 percent heavier — which translates into a roughly 30-pound gain. “At 195.5 pounds, put five American guys in a room and you’ve gathered roughly half a ton of manhood,” Ingraham notes. In the same period, women’s weight shot up from 140 pounds to just over 166 pounds — an 18.5 percent increase.

CDC

Thirty percent of the adult population in the US is now obese. (CDC)

Overall, 30 percent of the adult population is now obese. Since 1980, obesity rates more than doubled among adults and tripled among children.

The most basic explanation for how we got so fat

Though both men and women each added about an inch of height to their frames, a lot of the weight gain can be attributed to the fact that Americans are eating a lot more — including more calorie-dense processed and restaurant food.

(USDA)

Food production increased since the 1960s, food prices went down, and people started taking in more calories — particularly processed foods.

The average American’s total caloric intake grew from 2,109 calories in 1970 to 2,568 calories in 2010. As Pew Research put it, that’s “the equivalent of an extra steak sandwich every day.”

There are many other hypotheses to explain what is driving obesity

But that’s not the only explanation. We’re also not getting enough exercise to burn off all the calories we’re taking in. According to the CDC, fewer than half of all adults now meet the Physical Activity Guidelines.

Modern-day Americans also eat fewer fruits and vegetables relative to grains, meat, dairy, and fat. Obesity experts agree that in order to maintain a healthy weight, plants should be a staple of every meal — yet fruits and vegetables make up a small proportion of the American diet.

(CPSI)

More than half of our food dollars are now being spent on restaurant foods and processed, convenient, on-the-go meals. You’re much more likely to pack on calories when you eat out. Compared with home-cooked meals, breakfasts at sit-down restaurants typically have 261 more calories, lunches have 183 more calories, and dinners have 219 more calories. That’s about 600 extra calories per day.

Added sugars — the sweeteners in processed foods like cakes and sugary beverages — also make up an increasingly large part of the American diet. Women should have no more than six teaspoons of sugar per day, and men no more than nine teaspoons. Yet the Center for Science in the Public Interest reported that the average American is now consuming 23 teaspoons of added sugar each day.

The increasing role sugar plays in the diet has become a popular explanation for the obesity epidemic. But many other causes have been blamed: salt, fat, French fries, Facebook, too little sleep, too much stress, chemicals in the environment, and even viruses. While every one of these theories is a compelling explanation for the surge in obesity rates, what’s really driving the trend is probably a mixture of genetic, environmental, and behavioral factors.