Steven Blair is, in his own words, a “short, fat, bald guy.”
But at five-foot-five and 200 pounds, he may very well be healthier than
men much taller and leaner. He runs 25 miles a week, eats six to eight
servings of fruits and vegetables a day, and avoids processed and fatty
foods. A professor of exercise science and epidemiology at the
University of South Carolina, Blair is a living example of how fat
doesn’t play fair. And thanks to advances in his field, he is beginning
to understand why.
Robert Simon/istockphoto.com
Genes, hormonal imbalances, and even viruses are now acknowledged to
play a role in obesity. Eating less and working out more, in fact, don’t
have nearly as much to do with
weight loss
as you might assume. “This is all counter to what people think they
know,” says Blair. “You can see obesity, so it’s easy to say ‘Well, that
person must not be trying. He must be lazy.’ But that’s often not the
case.”
Our team pored over the latest studies, interviewed the top
clinicians in obesity science, and listened to the real-life experiences
of men and women struggling to maintain their weight. Here, the latest
(and often unexpected) thinking behind size and thighs, fatness and
fitness.
1. It Really Is Genetic
When scientists first discovered it in certain
chubby mice, they called it simply the fatso gene. Years later, when
they scoured the human genome for markers that increased vulnerability
to type 2 diabetes, the fatso gene (now more politely called FTO) showed
up there too. Turns out, people with two copies of the gene were 40
percent more likely to have diabetes and 60 percent more likely to be
obese than those without it. Those with only one copy of the gene
weighed more too.
Scientists now suspect that there are lots of fat genes. “There could
be as many as 100 of them,” says Claude Bouchard, PhD, executive
director of the Pennington Biomedical Research Center at Louisiana State
University System, “each adding a couple of pounds here and a pound or
two there. That’s a noticeable difference when it comes to how much more
fat we need to burn off.”
As much as 16 percent of the population has two copies of the FTO
gene, and half of us have one copy. So far, scientists suspect that the
other possible obesity-promoting genes have a small effect compared with
FTO. The good news? “A genetic predisposition isn’t necessarily a life
sentence,” says Bouchard. Exercising regularly can offset the risk.
2. Some People Just Have More Fat Cells
And the range is enormous, with some people having twice as many fat
cells as others have, says Kirsty Spalding, PhD, of the Karolinska
Institute in Stockholm. Even if you’ve lost a few pounds (or gained
some), your fat-cell count remains, holding tight to the fat already
inside and forever thirsting to be filled up with more. (To add insult
to injury, the fat cells of overweight and obese people hold more fat
too.)
New fat cells emerge during childhood but seem to stop by
adolescence. Those of us destined to have a lot of these cells probably
start producing them as young as age two. The cells’ rate of growth may
be faster, too—even if kids cut way back on calories.
Strangers have written to Spalding, telling her how depressed they
are by her research. But she says her news isn’t all bleak. You’re
better off with more fat cells, she says, than with fewer fat cells that
become overstuffed and enlarged. (New research suggests that the
overstuffed group are more vulnerable to obesity-related health
complications.) So while
you can’t reduce your total number of fat cells, there are things you can do to keep them small. (See next point.)
3. You Can Change Your Metabolism
Another Scandinavian team looked into what happens at the cellular
level when you gain weight. Kirsi Pietiläinen, PhD, an assistant
professor of nutrition at Helsinki University Central Hospital, studied
sets of twins where one was fat and the other thin, and learned that fat
cells in heavier twins underwent metabolic changes that make it more
difficult to burn fat. Pietiläinen’s team suspects that gaining as
little as 11 pounds can slow metabolism and send you spiraling into a
vicious cycle: As you gain more fat, it becomes harder to lose it.
How to get back on track? “The more I learn on the job, the more I’m
convinced we need physical activity,” Pietiläinen says. Once a chubby
child herself, she now runs regularly and is at a
healthy weight.
4. Stress Fattens You Up
The most direct route is the food-in-mouth syndrome: Stressful
circumstances (your bank account, your boss) spark cravings for
carbohydrate-rich snack foods, which in turn calm stress hormones. (When
researchers in one study took away high-carb food from stressed mice,
their stress hormones surged.)
Stress hormones also ramp up fat storage. For our prehistoric
ancestors, stress meant drought or approaching tigers, and a
rapid-storage process made sense; we needed the extra energy to survive
food shortages or do battle. Today we take our stress sitting down—and
the unused calories accumulate in our midsection.
To whittle yourself back down to size, in addition to your usual
workout routine, make time for stress relief—whether it’s a yoga class
or quality time with family.
5. Mom’s Pregnancy Sealed Your Fate
A mother’s cigarettes increase the risk of low birth weight, and
alcohol can damage her baby’s brain. So why wouldn’t unhealthy foods
wreak similar havoc? A growing body of science suggests that sugary and
fatty foods, consumed even before you’re born, do exactly that. A
Pennington study on rodents reports that overweight females have higher
levels of glucose and free fatty acids floating around in the womb than
normal-weight ones do. These molecules trigger the release of proteins
that can upset the appetite-control and metabolic systems in the
developing brain.
What’s true for mice is often true for humans too. Doctors from State
University of New York Downstate Medical Center compared children born
before their mothers had gastric bypass surgery with siblings born
later. Women weighed less after the surgery, as expected, but their
children were also half as likely to be obese. Because siblings have
such similar genetic profiles, the researchers attributed the weight
differences to changes in the womb environment. Moms-to-be, take note:
You can give your kids a head start by eating well before they’re born.
6. Sleep More, Lose More
When patients see Louis Aronne, MD, past president of the Obesity Society and author of the forthcoming book
The Skinny,
they’re as likely to have their sleep assessed as their eating habits.
If patients are getting less than seven to eight hours, Dr. Aronne may
prescribe more shut-eye rather than the latest diet or drug. With more
sleep, he says, “they have a greater sense of fullness, and they’ll
spontaneously lose weight.”
Why? University of Chicago researchers reported that sleep
deprivation upsets our hormone balance, triggering both a decrease in
leptin (which helps you feel full) and an increase of ghrelin (which
triggers hunger). As a result, we think we’re hungry even though we
aren’t—and so we eat. Indeed, sleep may be the cheapest and easiest
obesity treatment there is.
7. Your Spouse’s Weight Matters
When Jodi Dixon’s six-foot-two, 360-pound husband lost 125 pounds,
she had mixed feelings. She was the one who always watched her weight
and exercised; she was always the one trying to get her husband to be
more active. Mort, a medical sales rep, was always the life of the
party, says his wife, a 43-year-old mother of two in Freehold, New
Jersey. But when he lost the weight, it was different.
“Men and women would flock to him, drawn to his charisma,” she
recalls. “I felt jealous.” Dixon comforted herself with food and gained
20 pounds before she decided to take action. She began biking with her
husband and enrolled in a diet program. Eventually she trimmed down,
too, shedding 30 pounds, and has her sights on losing more.
Dixon credits the weight gain, and the loss, to her jealousy. But
research shows that weight gain and loss can be, well, contagious. A
study in the New England Journal of Medicine suggests that if one spouse
is obese, the other is 37 percent more likely to become obese too. The
researchers concluded that obesity seems to spread through social
networks.
As in Dixon’s case, slimming down seems to be catching, at least
within the family: When Dixon launched her weight-loss plan, her eldest
daughter, also overweight, followed her mom’s healthy habits and lost 40
pounds.
8. Achoo! A Virus Can Cause Obesity
Adenoviruses are responsible for a host of ills, from upper
respiratory tract problems to gastrointestinal troubles. The link to fat
was uncovered when researchers at the University of Wisconsin injected
chickens with the viruses and found that certain strains fattened them
up.
Stem cells, known for their chameleonlike abilities to
transform, also turned into fat cells when infected with the viruses.
“The virus seems to increase the number of fat cells in the body as well
as the fat content of these cells,” says Nikhil Dhurandhar, PhD, now an
associate professor of infections and obesity at Pennington.
Human studies, including comparisons of twins, suggest that obese
people are indeed more likely to harbor antibodies for a particular
virus, known as adenovirus-36.
We have flu shots; could an obesity vaccine be the next step? It may
sound far-fetched, but “that’s what they said about cervical cancer
too,” says Dhurandhar.
9. Cookies Really Are Addictive
While food is not addictive the way cocaine or alcohol is, scientists
in recent years have found some uncanny similarities. When subjects at
Monell Chemical Senses Center in Philadelphia were shown the names of
foods they liked, the parts of the brain that got excited were the same
parts activated in drug addicts. It may have to do with dopamine, the
hormone linked to motivation and pleasure, say researchers at Brookhaven
National Laboratory in Upton, New York. If obese people have fewer
dopamine receptors, they may need more food to get that pleasurable
reaction.
10. Ear Infections Can Taint Your Taste Buds
For years, the team at Linda Bartoshuk’s taste lab at the University
of Florida wondered why people who tasted food less intensely than
others seemed more likely to be fat. Researcher Derek Snyder had a
theory: Could an ear infection, which can damage a taste nerve running
through the middle ear, be the missing link? After tabulating 6,584
questionnaires, the team discovered that those over 35 who had suffered
several ear infections had almost double the chance of being obese.
Responses to additional questions provided clues as to why. Former
ear-infection patients were a little more likely to love sweets and
fatty foods—perhaps because the damaged nerve causes them to have a
higher threshold for sensing sweetness and fattiness. Even a small
increase in calories from bad food choices adds up over time.
Childhood ear infections are as hard to avoid as the colds that tend
to bring them on, but limiting passive smoke seems to drive down
incidents of ear infection. If you’re an overweight adult who suffered a
severe ear infection as a child, it may be worth paying attention to
the taste and texture of your food. Simply finding healthier
substitutes, such as fruit instead of candy, or olive oil instead of
butter, may help drive you toward eating better and weighing less.
11. Antioxidants Are Also Anti-Fat
Free radicals are now blamed not only for making you look old but
also for making you fat. Zane Andrews, PhD, a neuroendocrinologist at
Monash University in Australia, says these oxidizing molecules damage
the cells that tell us we’re full. Free radicals emerge when we eat
(something even the keenest dieter must do to survive), but they’re
especially prevalent when we gorge on candy bars, chips, and other
carbohydrates. With every passing year, these fullness signifiers suffer
wear and tear-causing the “stop eating!” signal to get weaker and
appetites (and possibly our stomachs) to get bigger. The best way to
fight back? Avoid the junk and load up on colorful, antioxidant-rich
fruits and vegetables.
12. Pick a Diet, Any Diet
As established diet books constantly reinvent themselves to sell
copies and win converts, a curious phenomenon has emerged: Ornish,
Atkins, and everyone in between are sounding remarkably similar. The
low-fat gurus now say that certain fats are okay, while the low-carb
proponents are beginning to endorse whole grains. With every new
guideline and selling point, each diet acknowledges that there are
really four basic rules to healthy eating (drumroll, please):
- Consume carbs in the form of whole grains and fiber.
- Avoid trans fats and saturated fats.
- Eat lean protein.
- Fill up on fruits and vegetables.
The low-carb South Beach Diet, for example, now espouses the virtues
of eating the Mediterranean way-including lots of carbohydrate-rich
fruits and vegetables. The latest Atkins book emphasizes the “good carb”
message too. Weight Watchers, a champion of the points system, is now
offering a “no counting” option based on healthy choices like those
above. Jenny Craig is pushing Volumetrics, a high-volume, low-calorie
strategy. And everyone gives a thumbs-down to processed and sugary
carbohydrates, which cause insulin to spike and can lead to more fat and
even diabetes.
Low-fat-diet guru Dean Ornish, MD, says, “It’s the end of the diet
wars.” His most recent book, The Spectrum, even offers recipes that can
be prepared in various “degrees”—from a vegetable chili served plain
(low-fat) to one served with olives (more fat) to still another served
with turkey breast sausage (still more fat).
The key to all of this, of course, is moderation rather than
deprivation—eating in a way you can live with. And for some people, an
important side effect of eating more plant-based foods is that it’s
better for the environment. (See food writer Mark Bittman’s
Simple Till Six: An Eating Plan for Busy People.)
13. You Can Be Fat and Fit
A growing body of literature suggests that size
doesn’t matter when it comes to your health. A study published in the
Archives of Internal Medicine surveyed 5,440 American adults and found
that 51 percent of the overweight and almost 32 percent of the obese had
mostly normal cholesterol, blood sugar, blood pressure, and other
measures of good health.
Further defying conventional wisdom, the article also reported that
23.5 percent of trim adults were, in fact, metabolically abnormal—making
them more vulnerable to heart disease than their heavier counterparts.
The latest U.S. Department of Health and Human Services report
corroborates what our doctors have said all along: You need about 30
minutes of moderate-intensity physical activity five days a week for
health. And you don’t even have to do your exercise in one fell
swoop—ten-minute stints of walking are just as effective. That means if
you forgo the elevators for the stairs, get off one train or bus stop
earlier, and park your car a few blocks away, chances are you’ll be good
for the day.
Remember Steven Blair, the self-described short, fat, bald guy? At
age 69, his blood pressure is in check, his cholesterol levels are
normal, and his heart is strong. What’s more, he may have even more
positive vital signs, according to his recent study in the journal
Obesity:
Men who are fit (determined by their performance on a treadmill) have a
lower risk of dying of cancer than out-of-shape guys, regardless of
their body mass index, waist size, or percentage of body fat.
The news is heartening, says Blair: “We don’t have great tools to
change people’s weight, but we know we can change their fitness levels.
New Way to Tame Cravings?
Some of the most eagerly awaited pills in the pipeline promise to calm cravings, reduce appetite, and even boost metabolism.
For instance,
vigabatrin has been studied as a
treatment for drug addiction. Suspecting that it would work on
weight-control patients, scientists injected the substance into obese
rats. It worked: The rats lost 19 percent of their original weight after
40 days.
Another drug,
tesofensine, works on three different
mechanisms in the brain to regulate appetite and metabolism. In early
trials, patients who used the drug lost an average of nearly 30 pounds.
So what’s the catch? Side effects. The much-hyped drugs taranabant
and Acomplia both failed because they caused severe mood swings and
depression. Scientists will have to pay close attention to dosage and
side effects if future weight-loss drugs are to clear the FDA approval
process.
