Cortisol and Weight
by Tiffany Spudich, PharmD
brought to you by Bellevue Pharmacy, a ProjectAWARE
Does stress affect eating, weight, and where fat is distributed
on the body? This is a question that has begged an answer from experts
for many years. The body makes cortisol to help us handle stress.
When stress goes up, cortisol levels go up. And it's often repeated
that obese people have higher cortisol levels than lean people.
Cortisol is a hormone in a group of steroids commonly referred
to as glucocorticoids. Cortisol is a hormone produced by the adrenal
gland as a part of your daily hormonal cycle. However, it is also
a key hormone involved in the body’s response to stress, both
physical and emotional. Cortisol increases blood sugar levels,
increases blood pressure, and suppresses the immune system, which
is part of the body’s fight-or-flight response that is essential
for survival. Your hypothalamus, via the pituitary gland, directs
the adrenal glands to secrete both cortisol and adrenaline.
Adrenaline production increases your alertness and energy level,
also increasing your metabolism by helping fat cells to release
energy. Cortisol has widespread actions which help restore homeostasis
after stress, including increasing production of glucose from protein
to quickly increase the body’s energy during stressful times.
However, cortisol has a two-fold effect on fat. When the stress
first occurs, fat is broken down to supply the body with a rapid
source of energy. When we experience something stressful, our brains
release a substance known as corticotropin-releasing hormone (CRH),
which puts the body on alert and sends it into "fight or flight"
mode. As the body gears up for battle, the pupils dilate, thinking
improves, and the lungs take in more oxygen. But something else
happens as well: Our appetite is suppressed, and the digestive system
shuts off temporarily. CRH also triggers the release of the hormones
adrenaline and cortisol, which help mobilize carbohydrate and fat
for quick energy. When the immediate stress is over, the adrenaline
dissipates, but the cortisol lingers to help bring the body back
into balance. And one of the ways it gets things back to normal
is to increase our appetites so we can replace the carbohydrate
and fat we should have burned while fleeing or fighting.
"But when was the last time you responded to stress with such
physicality?" asks Dr. Pamela Peeke asks, author of Fight
Fat AfterForty and an assistant clinical professor
of medicine at the University of Maryland School of Medicine. Your
body assumes you have just physically exerted yourself, for example
running from a lion, and need to restock your reserves by eating
a lot of carbohydrates or fatty food that can easily be stored as
fat. In reality, you are probably still sitting in your car or at
your desk, still fuming and stressed out. Dr. Peek notes that, “In
today's modern world, this elegant survival mechanism may be an
anachronism that causes the body to refuel when it doesn't need
to. Sustained stress keeps up cortisol, that cursed hunger promoter,
elevated and that keeps appetite up, too.”
This is where the potential second effect of cortisol comes into
play. Experts now believe that the problem for many of us
is being in a constant state of stress. Exposure to cortisol over
the long term can lead to weight gain, as your appetite and insulin
levels are continuously increased. If stress and cortisol levels
stay high, so will insulin levels, says Robert M. Sapolsky, Ph.D.,
a professor of biological sciences and neuroscience at Stanford
University. Continual stress leads to a constant state of excess
cortisol production, which stimulates glucose production. This excess
glucose then typically is converted into fat, ending up as stored
fat. According to Dr. Sapolsky, "The net effect of this will
be increased fat deposition in a certain part of the body."
Furthermore, according to the authors of the book The Cortisol
Connection, stress and the resulting chronic overload of cortisol,
make you feel tired and listless. So you overeat to renew your energy
and comfort yourself, with the end result of accumulated extra inches
around the middle.1
It is generally suggested that stress-induced cortisol weight is
usually gained around the waistline, because fat cells in that area
are more sensitive to cortisol. The fat cells in your abdomen are
richer in stress hormone receptors, are particularly sensitive to
high insulin, and are very effective at storing energy – more
so than fat cells you would find in other areas of the body. This
is the most dangerous place to gain weight, as it can lead to metabolic
syndrome, diabetes, and heart disease.
A recent study conducted by researchers at Yale University compared
women who stored fat primarily in their abdomens with women who
stored it mostly in their hips. They found that the women with belly
fat reported feeling more threatened by stressful tasks and having
more stressful lives. They also produced higher levels of cortisol
than the women with fat on their hips. And that, the authors reasoned,
suggests that cortisol causes fat to be stored in the center of
However, some researchers believe that cortisol’s connection
to obesity may be more unsubstantiated than first thought and that
cortisol levels may not be the sole, major factor involved in obesity
and fat distribution. There are questions as to whether cortisol
may rise prior to weight gain or if its increase is an impact of
the weight itself.
One area of research involves mutations in a gene called the proopiomelanocortin
(POMC) gene, which may cause obesity but simultaneously decreases
glucocorticoid levels. This research shows that cortisol alone may
not be major culprit in weight gain, and suggests that glucocorticoids
are merely part of a chain of hormonal and neuronal signals associated
"The message has gotten across that glucocorticoids are involved
in all obesity. And there is a lot of common talk about the role
of stress in increasing glucocorticoids," says Malcolm Low,
M.D., Ph.D., a senior scientist and associate director in the OHSU
Center for the Study of Weight Regulation and Associated Disorders.
"It seems to make sense: There is a lot of stress today, and
obesity is up. But when you look at the facts, it is not as clear."
Low notes, “There are multiple controls in our body that regulate
body weight and appetite. Glucocorticoids are clearly involved in
control of body weight. But it is not the only hormone involved.
There are multiple systems involved in the brain and outside the
brain that regulate how much fat we are going to have and how much
appetite. There is no simple answer to treating obesity."
Marci Gluck, Ph.D., of the New York Obesity Research Center at
St. Luke's-Roosevelt Hospital and Columbia University, studies the
complicated relationship between cortisol, stress, and weight gain.
"Most scientists agree that it is not a simple one-to-one relationship
between cortisol and weight gain," she says. "There are
so many different peptides and hormones involved. Cortisol might
not be the primary one."
Based on a review of literature addressing obesity and cortisol
status, the two most integral lab parameters to assess systemic
cortisol status and its relationship to obesity is measurement of
daily cortisol production rate (CPR) and measurement of 24-hour
mean plasma cortisol concentrations.4-7 Thus far, few
studies have utilized these parameters for measurement of cortisol
concentration in obesity, and of the studies that have been done
using these parameters, none of these publications has reported
elevated plasma cortisol concentrations in obese individuals.7,
However, recent reports have suggested that a state of elevated
cortisol levels in fat tissue cells without elevated cortisol levels
in the blood may exist in obesity.4 Yet, these findings are inconsistent.
It is possible that high levels of cortisol within the cells, such
as in fat cells, may play a causative role in obesity, but this
possibility requires further investigation.
If we do accept that chronic stress and elevated cortisol may be
factors in weight problems, what can you do if you want to reduce
cortisol? First, focus on becoming stress resistant. One of the
best things to reduce stress and improve insulin sensitivity, for
example, is getting regular exercise, even a daily brisk walk. Exercise
not only helps promote weight loss by burning calories, but is also
beneficial because it helps neutralize stress and its effects, which
in turn helps you keep weight off. Just a daily brisk walk
can help to distract yourself from what is causing stress in your
life, allowing your body time to move and awaken.
Second, practice stress reduction techniques such as meditation,
yoga, and breathing exercises. Improving time management can also
be essential to reducing stress in one’s hectic lifestyle.
These activities or similar techniques, as well as getting adequate
sleep, can help reduce your body’s physiological response
to daily stressors.
Third, how a person perceives stressful situations is also important.
One individual may feel major stress from a particular situation,
whereas another person will handle it better by using the event
as an opportunity to learn. Hence, stress makes life difficult,
but our reaction to it is important as well.
- Talbot S, Kramer W. The Cortisol Connection. 1st ed.
Berkeley, CA: Publishers Group West, 2002.
- Epel ES, McEwen B, Seeman T, Matthews K, Castellazzo G, Brownell
KD, Bell J, Ickovics JR. Stress and body shape: stress-induced
cortisol secretion is consistently greater among women with central
fat. Psychosom Med. 2000 Sep-Oct;62(5):623-32.
- Smart JL, Tolle V, Low MJ. Glucocorticoids exacerbate obesity
and insulin resistance in neuron-specific proopiomelanocortin-deficient
mice. J Clin Invest.2006 Feb;116(2):495-505. Epub 2006 Jan 26.
Erratum in: J Clin Invest. 2006 Mar;116(3):842.
- Salehi M, Ferenczi A, Zmoff B. Obesity and Cortisol Status.
Horm Metab Res 2005;37:193-197.
- Prezio JA, Carreon G, Clerkin E, Meloni CR, Kyle LH, Canary
JJ. Influence of Body Composition on Adrenal Function in Obesity.
J Clin Endocrinol Metab 1964;24:481-485.
- Streeten DH, Stevenson CT, Dalakos TG, Nicholas JJ, Dennick
LG, Fellerman H. The diagnosis of hypercortisolism. Biochemical
criteria differentiating patients from lean and obese normal subjects
and from female on oral contraceptives. J Clin Endocrinol Metab
- Jessop DS, Dallman MF, Flaming D, Lightman SL. Resistance to
glucocorticoid feedback in obesity. J Clin Endocrinol Metab 2001;86:4109-4114.
- Hellman L, Nakada F, Curti J Et al. Cortisol is secreted episodically
by normal man. J Clin Endocrinol Metab 1970;30:411-422.
- Chalew SA, Nagel H, Burt D, Edwards CR. The integrated concentration
of cortisone is reduced in obese children. J Pediatr Endocrinal
Metab 1997; 10: 287-290.
- Chalew SA, Lozano RA, Armour KM, Zadik Z, Kowarski AA. Reduction
of plasma cortisol levels in childhood obesity. J Pediatr 1991;
- Strain GW, Zumoff B, Kream J, Strain JJ, Levin J, Fukushia D.
Sex difference in the influence of obesity on the 24 hr mean plasma
concentration of cortisol. Metabolism 1982: 31: 209-212.
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