Why we're so fat
If obesity is a disease, like cancer or heart disease, as
researchers stress, it is time to stop blaming lack of willpower for the
poundage and ask — non-judgmentally — why are we so fat? From better
foods that mimic drugs, the answers may shake up your diet.
In 1998, 29 million people suddenly became <a href="http://www.livescience.com/topic/obesity">overweight</a> without
an ounce. That summer, the U.S. government announced new guidelines
the threshold of what classifies a person as overweight. Previously, if
body mass index (BMI) was less than 28 for men, or 27 for women, you
considered "normal." Now only BMIs of 25 or below are considered
healthy. (BMI is a ratio of weight to height, and is considered an
how much body fat a person has.)
While our food-stuffed, exercise-starved, modern lifestyles
are still the most popular scapegoats, in the future, we might also
frequent hand-washing and cleaner water.
In experiments done on mice, researchers have found that
certain intestinal bacteria can help a body suck more calories out of
amount of food and even increase a person's <a href="http://www.livescience.com/health/091222-aroma-stomach.html">appetite</a>.
It is possible these bacteria gained prominence as we wiped out
bacteria with antibiotics and better hygiene practices, said senior
Andrew Gewirtz at the Emory University School of Medicine in Georgia.
The finding does not suggest that obesity is an infectious
disease — it is nearly impossible to change your intestinal helpers
first few years, or even days, of life — so don't expect an obesity
Not everyone has succumbed to environmental changes: Skinny
people do still exist. These people have won "the throw of the genetic
dice," said Susan Carnell, an obesity researcher at the Columbia College
of Physicians and Surgeons in New York.
Genes likely control how easily one feels satiated,
researchers are finding. People who lack the genes for a voracious
often don't understand how hard it is for someone who isn't so
lucky, Carnell said.
New research has shown that an unborn child may receive
messages in the womb about how to regulate his or her weight.
the idea that even if genes themselves aren't altered, how they function
Researchers at the Arkansas Children’s Nutrition Center in
Little Rock transferred the newborns of normal-weight and obese rat
"dams," to the care of svelte females. Even with nearly identical
genes and upbringing, only the babies from the wombs of the rotund
"This occurred despite the fact that the offspring of
overweight dams ate the same amount of high-fat food as the offspring of
dams," said study researcher Kartik Shankar in a press statement.
People judge their own weight based on that of others and,
well, in the land of the obese, the overweight feel superior. Research
shown that if your <a href="http://www.livescience.com/health/070725_fat_friends.html">friends
fat</a>, you are more likely to join the big booty camp yourself — even
obese pals live far away. An underlying reason might be a resetting of
consider normal, so a scale reading above a certain point could have
into tears one day and barely gotten notice the next. Such findings
that obesity has cultural and psychological causes as well as
Cars, chairs and sofas
We don't move our bodies nearly as much as our
hunter-gatherer ancestors, a fact that has likely contributed to our
weight gain. Exercise is great for maintaining weight and regulating
But if you want to lose a bulge, or ten, and "you are
not <a href="http://www.livescience.com/topic/diet">reducing calories</a>,
exercising, it will take a very long time to lose a single pound," said
Caroline Apovian, an obesity researcher at the Boston University School
The food fun house
"If McDonald's didn't exist, we'd all be a lot
thinner," Carnell said, referring to fast foods in general.
Highly <a href="http://www.livescience.com/health/top_10_good_food_bad.html">palatable
foods</a>, such as those available from fast food chains, are "layered
loaded with fat, sugar and salt," all of which, instead of satiating us,
actually prompt us to continue eating, said Dr. David Kessler, former
commissioner and author of "The End of Overeating" (Rodale Books,
2009). Such foods cause particular excitement in areas of the brain
with emotion and reward — much like alcohol, sex and drugs.
With sugar, salt and fat on every street corner, Kessler
said, "we are living in a food carnival." And like an over-stimulated
preschooler glazing over with fatigue and irritability, our bodies are
to the food fun house by developing insulin resistance, diabetes and
inflammation, which is a body-wide immune response that has been linked
with health issues, including heart disease and cancer.
The national eating disorder
While genes and environment are responsible for two-thirds
of the differences in people's BMIs, the remaining third is
psychological. Not only can our jam-packed lifestyles drive us to
food, stress and lack of sleep may take an unfriendly toll on
The U.S. food culture, or lack thereof, is also to blame, Kessler said.
Unlike other developed countries, which have been slow to match our
rates, we put limited value on the pleasures and rituals of dining —
eaten at our desks, breakfast on the commute.
Such disrespect for food likely exacerbates weight problems
by leaving us perpetually unsatisfied. Tellingly, <a href="http://www.livescience.com/health/091104-quick-eating.html">eating
has been linked to being overweight while <a href="http://www.livescience.com/health/childhood-obesity-prevention-100208.html">regular
meals</a> are associated with a decreased risk of obesity.