Monday, July 20, 2009

America is Getting Fatter

There's a great piece in the New Yorker this week (I especially love the cover art):

This part is particularly interesting:

"Men are now on average seventeen pounds heavier than they were in the late seventies, and for women that figure is even higher: nineteen pounds. The proportion of overweight children, age six to eleven, has more than doubled, while the proportion of overweight adolescents, age twelve to nineteen, has more than tripled. (According to the standards of the United States military, forty per cent of young women and twenty-five per cent of young men weigh too much to enlist.) As the average person became heavier, the very heavy became heavier still; more than twelve million Americans now have a body-mass index greater than forty, which, for someone who is five feet nine, entails weighing more than two hundred and seventy pounds. Hospitals have had to buy special wheelchairs and operating tables to accommodate the obese, and revolving doors have had to be widened—the typical door went from about ten feet to about twelve feet across. An Indiana company called Goliath Casket has begun offering triple-wide coffins with reinforced hinges that can hold up to eleven hundred pounds. It has been estimated that Americans’ extra bulk costs the airlines a quarter of a billion dollars’ worth of jet fuel annually."

What's been going on since the 1970's that could have lead to Americans gaining so much extra weight? The article discusses "upsizing" or portions, but my guess is that instead of focusing on just eating less and exercising more, we've become obsessed in chasing the latest miracle fat loss diet. The end result is that we've gained weight overall instead of losing it.

This part is also interesting:

"Although no one really knows what life was like in the Pleistocene, it seems reasonable to assume that early humans lived, as it were, hand to mouth. In good times, they needed to stockpile food for use in hard times, but the only place they had to store it was on themselves. Body fat is energy-rich and at the same time lightweight: when the water is taken out, a gram of fat contains 9.4 kilocalories, compared with 4.3 kilocalories for a gram of protein, and when the water is left in, as it is on the human belly, a gram of fat still contains 9.1 kilocalories, while a gram of protein has just 1.2. As a consequence, a person with a genetic knack for storing fat would have had a competitive advantage. Power and Schulkin are both researchers at the American College of Obstetricians and Gynecologists, and they argue that this advantage would have been especially strong for women. Human infants are unusually portly; among mammals, only hooded seals have a higher percentage of body fat at birth. (Presumably, babies need the extra reserves to fuel their oversized brains.) Tellingly, humans, unlike most other animals, have no set season of fertility. Instead, ovulation is tied to a woman’s fat stores: those who are very thin simply fail to menstruate.
Of course, for early humans putting on too many pounds would have been a significant disadvantage; it’s hard to chase down a mastodon or track through a forest if you’re tubby. Thus, there would appear to be a Darwinian argument against obesity as well. Power and Schulkin get around this problem by noting that, as a practical matter, opportunities for eating too much were limited. Austerity was the rule for hunter-gatherer societies, and that didn’t change when people started to form farming communities, some ten thousand years ago. In fact, human remains from many parts of the world show that early agriculturalists were less well fed than their Paleolithic forebears; their skeletons are several inches shorter and often show signs of nutrition-related diseases, like anemia. Genes that controlled weight gain wouldn’t have been selected for because they simply weren’t needed.
In America today, by contrast, obtaining calories is very nearly effortless; as Power and Schulkin observe, with a few dollars it’s possible to go to the grocery store and purchase enough sugar or vegetable oil to fulfill the average person’s energy requirements for a week. The result is what’s known as the “mismatch paradigm.” The human body is “mismatched” to the human situation. “We evolved on the savannahs of Africa,” Power and Schulkin write. “We now live in Candyland.” "

See, as I been writing, NOT EATING for a period of time is actually quite natural-- contrary to what food companies want you to believe. Our bodies evolved to go through famine periods by using up the fat stores in our bodies. What is actually NOT NATURAL is eating three caloric dense meals a day, 365 days a year.

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