Showing posts with label nutrition. Show all posts
Showing posts with label nutrition. Show all posts

Wednesday, February 16, 2011

New Dietary Guidelines: Hailed, Hackneyed and--a Cause of Obesity?

Big praise everywhere for the brand-new Dietary Guidelines for Americans, just released by the US Departments of Agriculture and Health. But why?

Apparently, previous guidelines had tip-toed on eggshells so as not to offend well-subsidized farmers and interest groups.  Fast food corporations pay good money in taxes, so the Feds didn't want to suggest that Supersized Fries should feed three, or that the Colonel quit serving chick wings you have to blot with paper towels to eat.

The Guidelines come out every five years by law, and the last one, in 2005, had very similar recommendations, just in less directive language. We've all been hammered with this same nutritional info since the first report in 1980. Every kid who's ever taken Health in junior high school has been tested on it.  Anyone who walks down a supermarket aisle gets a refresher course: "Now, with more fiber!" reads a label.  "And here's a great way to get those five servings of fruits and veggies!" chirps some food guru on a flat-screen TV in the produce section or over the check-out stand.

Let's see, do we want the margarine with the trans-fats or without??  The boastful red ZERO on the tub assures us no grams of that nasty heart-clogger lurk inside.

The problem is that despite redundant emphasis on less sweet and processed food, more fruits and veggies, more fiber and whole grains, less soda and salt--you know the drill--Americans have just gotten fatter.  Frankly, the statistics on obesity are a bit different from what we're led to believe, and I'll discuss them momentarily, but the result of the Feds' urging us to watch our dietary consumption is the opposite of their aim.  Knowledge and ubiquitous publicity about "shoulds" of nutrition have only brought a chunkier population. At the conclusion of this post, I'll tell you why.

In any case, with Michelle Obama adopting obesity-remediation as her personal campaign, we're sure to hear more...and more about it. Let's move!

Obesity stats: First off, a major caveat that the Centers for Disease Control uses the measure of BMI, "body mass index," which is notoriously crude, but all we've got. Every few years, statisticians of the NHANES program of the National Center for Health Statistics go out and take measurements on a sample using consistent methods, and classify subjects into three categories of heft, "overweight," "obese," and "extremely obese."


Now, here's the interesting thing: For adults over age 20, the "overweight," (BMI between 25 and 30) percentage of the population has stayed consistent for 50 years.  It was 31.5% in 1960-62, and 32.3 at the next measurement, 1971-4, compared to the latest figures from 2007-8 when 33.6% were overweight.  In 2005-6, "overweight" subjects were 32.2%, a tenth of a percentage LOWER than the figure for 1971-74.

The situation for the category called "obese," (BMI between 30 and 40) expanded from 13.4% at the 1960-62 first measurement to 15% in 1980. But then--at the next measurement (1988-94), there was a jump to 23.2%. And by the following measure, 1999-2000, the "obese" category swelled to 30.9%. That's a one-hundred-percent increase in just ten years! If people continued ballooning at the same pace, we'd expect to see 60% of the population "obese" by 2010--what a thought!

But there's a different outcome. Let me quote Katherine M. Flegal, et. al, a foremost researcher on obesity trends, in the Journal of the American Medical Association, (January 20, 2010—Vol 303, No. 3, page 235):

"In 2007-2008, the prevalence of obesity was 32.2% among adult men and 35.5% among adult women. The increases in the prevalence of obesity previously observed do not appear to be continuing at the same rate over the past 10 years, particularly for women and possibly for men."

Finally, stats regarding the "extremely obese" (BMI more than 40) are downright scary. In 1962, just .9% of the population--less than one percent--fell into that category. By 1976-80, the percentage was up to 1.4%. At the next measurement, 1988-94, the percentage doubled, to 3.0; by 2000 it was 5.0, and by 2005-6, it was 6.2%. The latest (2008) numbers show a slight drop, to 6.0%. The percentage of "extremely obese" mushroomed five hundred percent from 1962.

Why do I go through all these figures? Because they show that in the 20 years between 1980 and 2000, the rate of obesity skyrocketed. But it varied little before and after that period. Curious.

Do we blame those twenty years of thickening on McDonald's (which already had 1,000 restaurants by 1968) and fast food? On companies that added thousands of products to store shelves to answer working women's demand for convenience? On sloth encouraged by TV and the new lure of computer games? Or...could it be due to a virus (adenovirus 36)?  Hard to tell.

And do you believe it's education that suddenly stopped that steep climb in obesity a decade ago?


The authors of the 112 pages of the current "Dietary Guidelines"  (really only 59 pages of written content before all the appendices) would have us think so. Their recommendations are written in such lofty, vague, sweeping, academic and sometimes, hysterically funny prose as to render them flaccid.  And of course, the document recommends lots more government studies and commissions and interventions and regulations and education efforts as the way to shrink the citizenry. And inflate the budget.

Then, in a final chapter, the Guidelines acknowledge:
Although more consumer education is needed on achieving calorie balance, meeting nutrient needs, and staying physically active, information alone does not lead to behavior change.

Yes, that's right. You can lead a kid to water, but you can't make him drink (if there's soda handy), as the barage of healthy-eating information over the last thirty years has demonstrated.  Additional commissions and partnerships and studies likely won't work to reduce us either, if propping fan mags featuring skinny movie stars right where you buy your food can't inspire purchasers to slim down.  Shoppers ingest the magazine's cheesecake photos as they're loading their Haagen Dazs onto the conveyor belt.

Every market contains vegetables, a far wider variety of them than when I was growing up, including microwave-ready pouches you just nuke for five minutes and fork into.  Just about everyone has access to healthy food as well as the simply satisfying kind, the neck-up tranquilizers that offer rewarding crunches to salve frustration, or creamy smoothness to comfort.  Anybody can put on tennis shoes and go for a jog, or a walk, or climb the stairs in the building--they just don't.  The Guidelines are likely useless, but okay, if they mean there will be less junk in junk food, great.

I believe, however, that the Guidelines and experts telling Americans what they should eat and do are actually causing obesity, because they teach us to not trust our own instincts, to detach from our natural signals of hunger and satiation, and to override the internal mechanism that tells us what it is our bodies need right then.

If we could stop saying that sugar and ice cream are "bad" and celery and apples are "good," we just might clear the way to understand what our naturally thin grandparents did:  you eat when you're hungry, eat what pleases you, and move on to other activities when comfortably sated.  If it were possible to respect our individual likes and dislikes and toss out pyramids that once were squares, perhaps we could be at peace enough to relax about food and get on with actually developing our talents and minds and accomplishments.

One of the most humorous parts of the Dietary Guidelines is a silly diagram (6:1) of all the influences on people's eating and exercise habits.  Using colored ovals and arcs, we get a list of everything a bunch of people could brainstorm, including religion, community design and safety, food service and retail establishments, body image.  The one influence on what we eat that was completely absent from the 24 items packed into 4 sub categories was--body cues.  Hunger.

In other words, the authors of the august Dietary Guidelines for Americans 2010 believe eating choices are completely determined by factors external to the body consuming the food.

Certainly, the choice of particular foods that might satisfy one's body needs is shaped by factors like the cuisine of his family, or what's available.  But what's behind the idea of, say, "I feel like having a hamburger" versus "feeling like" having any other item on the menu?  The Dietary Guidelines would have us disregard the natural messages that tell us what we need nutritionally in favor of chewing some tasteless whole-grain lump, or even a tasty whole-grain lump that wasn't what our bodies needed at that moment.

I realize I'm going against the grain, but the Guidelines' emphasis on distinguishing bad from good foods turns attention from the primary source of food choices, which should be the body's communication of its needs, rather than a Federal Department or even the First Lady.