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Why Stress Tips the Scales |
E-Newsletter No. 26
Why Stress Tips the Scales
Frayed nerves increase our desire for carbohydrates and fat. And, if the pressure is
chronic, we try even harder to hold on to those pounds.
Lynn Butler has never been seriously overweight. In fact, if you ate lunch with her, you
would think she was a model eater. But the 57-year-old's ovo-lacto-vegetarian diet
degenerates into chaotic, solitary chocolate candy binges when she's upset.
With lots of exercise, Butler managed to stay a size 6 for most of her adult life. But two
years ago a stress fracture curtailed her exercise, and her eating got so out of control
that she gained 35 pounds. The depressing weight gain exacerbated the problem. "The
more uncomfortable your clothes become, the more stress eating you do," she says.
Butler is far from alone. Sixty percent of Americans are overweight or obese, and many of
them say that their eating habits worsen when they are stressed. Says Jean Curtis, a
spokesperson for the American Dietetic Assn.: "Everybody deals with stress, and food
happens to be one of the things they're manipulating. This is the reality in today's
world." Out-of-control eating and weight gain may seem like an irrational,
self-destructive response to stress. But food binges and weight gain make biological
sense. Under stress, the brain shifts into self-preservation mode, unleashing an array of
chemicals and hormones that protect the body from physical danger.
An essential survival mechanism when our ancestors expended lots of energy dodging
mountain lions and wrestling with heavy farm equipment, this fight-or-flight response
backfires in these sedentary times, when most of our stressors are of the nonphysical sort
like IRS deadlines and crashing computers.
Those who have not inherited resilient bodies and minds that can shrug off traffic jams
and long lines at the supermarket are more likely to continually enter this
self-protective mode. Ultimately, not only do the stress hormones make them hungry, they
also make them more likely to pack on the pounds.
Says Dr. Pamela Peeke, a professor of medicine at the University of Maryland who studied
the link between weight and stress at the National Institutes of Health: "There is no
question that chronic stress can make you fat."
Of course, chronic stress can trigger a number of other medical conditions, including
memory loss, hypertension and heart disease. But bariatric physician Dr. Paul Rivas,
author of "Turn Off the Hunger Switch," says that unlike those conditions,
"emotional" overeating is seen as a character flaw when it leads to excess
weight.
Rivas tells his guilt-ridden patients that their compulsion to overeat is a biological
flaw, not a character flaw: "It is not because you lack willpower or self-control.
You don't even know what you're doing. You're grabbing the food. It's compulsive. You're
into a survival mechanism."
A Hormonal Cascade Causes Ravenous Hunger
When this stress response is activated, the brain releases a chemical called
corticotropin-releasing hormone, or CRH, that suppresses appetite. The adrenal glands then
secrete their powerful fight-or-flight stress hormones, adrenaline and cortisol, which
propel sugar into the bloodstream for a short-term energy rush.
After that rush, cortisol sparks ravenous hunger for carbohydrates and fat. "When
you're all stressed out, the last thing you reach for is a can of tuna," says Peeke.
(She notes that "stressed" is "desserts" spelled backward.)
Worse, we do not give our bodies the downtime they expect after surviving a close call.
Instead, we tax our fight-or-flight response by activating it throughout the day as we
move from long commutes to demanding bosses to looming day-care pickup deadlines.
The result is prolonged, elevated cortisol levels that spur the release of insulin, the
hormone that directs the body to hang on to the fat it has and store more. "If you
have lots of stressors, you have lots of periods of rebound insulin secretion. The
cumulative effect is a push toward obesity," says Robert Sapolsky, professor of
biological and neurological sciences at Stanford University School of Medicine.
Stacking the biochemical deck further, the brain's complex appetite and satiety control
system can go haywire under stress. Rivas says that even if his patients were lounging on
a Tahiti beach, they would have to fight against their drive to overeat. Most people who
overeat when stressed, he says, are genetically prone to an imbalance among at least three
of the brain's neurotransmitters, serotonin, dopamine and norepinephrine, which help the
body regulate both appetite and mood.
Add ornery children and late mortgages to the equation and, says Rivas, "everything
gets worse." For example, when an already short supply of serotonin dwindles further
under stress, overeaters launch into desperate forays for sweets because carbohydrates,
unlike tuna fish, raise serotonin levels.
There are no reliable estimates of the number of stressed Americans who desperately scarf
down too much food. Weight statistics, for example, don't give a complete picture because
they miss some thin stress overeaters who compensate for their binges by starving
themselves or exercising maniacally.
However, it is clear that many Americans who are overweight are stress overeaters. Cynthia
Graff, chief executive of the 31-year-old Lindora Weight Loss Clinics, says her clients
are increasingly asking for help not just with their eating, but with their frazzled
lives: "They're not saying, 'I need to lose weight.' They're saying, 'My life is out
of control.'"
Though they may seem like oddities in this increasingly overweight country, there are
those who turn away from food when they feel their lives are out of control. Peeke says
biology is destiny for these "stress undereaters" as well: "Their
biological instinct is to reject food." Stress undereaters exhibit "very
high" levels of the appetite-depressing CRH, which trumps cortisol's
appetite-enhancing properties. Peeke notes that anorexics have some of the highest levels
of CRH ever measured in humans.
Even stress overeaters may shift to undereating in the wake of catastrophic stress, like
the death of a parent or a divorce. When 42-year-old Bay Area marketing consultant Elisa
Williams got divorced five years ago, she lost 20 pounds in a few weeks, down from a size
10 to a size 6. She splurged on a mini-sized wardrobe.
After four months she gained the weight back; her mini clothes are still hanging in her
closet. "Divorce weight doesn't last long," says Williams. Now she warns other
women going through divorce to refrain from spending big bucks on a divorce wardrobe.
That's great advice, because tight-fitting clothes can be a powerful stressor, especially
for women. Women are more likely to stuff themselves when they're anxious and more likely
to feel guilty about it, according to Alice Domar, a professor at Harvard Medical School
and director of the Mind/Body Center for Women's Health at Beth Israel Deaconess Medical
Center in Boston: "When a man gains 10 pounds he buys a new pair of pants. When a
woman gains 10 pounds she hates herself."
Very Restrictive Diets Are Often Counterproductive
To shed those stress-related pounds and stop stress overeating, experts offer a range of
solutions, including restrictive diets. But Domar warns against strict diets because they
often backfire. When rigid dieters fall off the wagon by eating a food on their forbidden
list, "They experience the 'What the hell' effect, then go and eat for the rest of
the day like crazy," she says.
Domar teaches an "80/20" plan that focuses on eating healthy foods 80% of the
time; 20% of the time her clients eat whatever they want. "You remove the guilt so
they get less stressed," says Domar.
Rivas, many of whose patients have lost weight with "boot camp" food regimens
only to find that they regain that weight and more, doesn't believe in restrictive diets
either. He prescribes drugs that balance some of the brain's neurotransmitters and
believes that genetically unlucky stress overeaters will likely need to take the drugs in
low dosages for the rest of their lives.
Rivas concedes that the drugs do not work for all stress overeaters, but says that's
because scientists have yet to completely unravel the complicated mechanisms that link
food and stress: "They have brain chemistries that we don't yet understand."
Tom Riley, 49, says the drugs have been a godsend for him: "For the first time in the
last 15 years I know what it is to be hungry. I had forgotten what it was like."
Riley, who works in intelligence at the Department of Defense, says that since Sept. 11
the pace at work has been frenetic. Work-related and other stresses used to intensify his
cravings for the peanuts, doughnuts and chocolate chip cookies that pushed his weight to
an all-time high of 305. No more. Riley is now eating like his naturally thin wife, who
never turns to food when she is under pressure, even though stress is "just as hard
on her" as it is on him.
But some clinicians worry about the long-term safety of such drugs, especially since 1997
when the popular weight-loss drug fenfluramine was taken off the market because it was
linked to heart valve damage. In addition, those who counsel stress overeaters argue that
in most cases the drugs are not necessary.
"I believe individuals can learn methods to identify how they respond to stress and
how not to let food be the only solution," says dietitian Jean Curtis. Popular
behavioral therapies include journals in which overeaters connect their emotions to their
eating, the substitution of a nurturing, nonfood treat--like a bubble bath--for
self-destructive overeating, and stress management techniques like biofeedback.
Dr. Paul Rosch, president of the American Institute of Stress, warns that there is no
magic destressing technique that works for everyone: "You have to find something you
enjoy and will adhere to rather than complying with some regimen you will most likely quit
after a short time."
Similarly, therapists urge their patients to find an exercise regimen they like. The
morphine-like endorphins released during exercise help dissipate stress hormones,
providing the release that humans used to get when they led more physical lives.
Now that her stress fracture is healed, Butler is back to the exercise she loves,
long-distance running. When she was a "severe sugar addict" she used running not
just for the joy of it, but also to "combat the calories of cake and candy."
With her doctors help, she has lost 14 pounds and considers herself a reformed sugar
addict.
Butler says she changed her eating habits by changing her thinking habits. She has let go
of the notions that she has to eat perfectly every day and that she can control everything
in her life.
It's an attitude that comes naturally three miles into her runs, when she experiences an
endorphin-induced "runner's high." Butler's lengthy to-do list disappears, she
becomes philosophical about the stress in her life and she looks for peace within herself,
not in a bag of peppermint patties.