TUESDAY, June 28, 2011 (Health.com) — Over the past several decades Americans have steadily gotten fatter. Although our increasingly sedentary lifestyles are partly to blame, a big reason for our national weight gain is that we’re simply eating more.
In the mid-2000s, government surveys show, the average American adult ate about 2,375 calories per day, nearly one-third more than he (or she) did in the late 1970s. What accounts for all those added calories?
According to a new study, the biggest single contributor to the sharp rise in calorie intake has been the number of snacks and meals people eat per day. Over the past 30-odd years, the study found, Americans have gone from consuming 3.8 snacks and meals per day to 4.9, on average—a 29% increase.
The average portion size has increased, too, but only by about 12 percent. And, surprisingly, the average number of calories per 1-gram serving of food (known as “energy density”) actually declined slightly over that period, which suggests that calorie-rich food has played a relatively minor role in our expanding waistlines.
“The real reason we seem to be eating more [calories] is we’re eating often,” says the lead author of the study, Barry Popkin, Ph.D., a professor of nutrition at the University of North Carolina at Chapel Hill. “The frequency of eating is probably, for the average overweight adult, becoming a huge issue.”
Popkin blames food advertising and other marketing for the shift from three square meals a day to near-constant eating.
“It’s all about making people think they want to have something in their hands all the time,” he says. “Why are we snacking all the time and munching all the time? [Food] is there, it’s available all the time, it’s tasty. It’s not very healthy, but it’s tasty. It’s sweet, it’s salty, it’s fatty—it’s all the things we love.”
Lisa Young, Ph.D., an adjunct professor of nutrition at New York University and the author of The Portion Teller, agrees that the ubiquity of snack foods has helped drive overeating.
“You never used to see food staring you in the face when you went to…a drugstore,” says Young, who was not involved in the new research. “It’s in your face and it’s cheap. You go get a magazine, you can get a candy bar.”
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