Learning Center
Studies Suggest That Sleep Deprivation May Cause
Weight Gain
Over the past few years, researchers around the globe have found
convincing links between sleep deprivation and weight gain.
One study conducted at the New York Obesity Research Center involved 30 men and women of roughly normal weight. The participants were had one five-night period where they were allowed to sleep 9 hours nightly. On a separate five-night visit, they were only allowed to sleep 4 hours nightly. The participants were found to burn the same number of calories regardless of their sleep duration. On the other hand, when sleep-deprived, the participants ate 300 calories more daily than when well-rested. The researchers note that this excess intake, if extrapolated over months and years, might easily result in significant weight gain in the sleep-deprived population.
A separate study, published in the American Journal of Clinical Nutrition, by researchers in Sweden found that decreased metabolism with just a single night’s sleep deprivation.
Other scientists have identified convincing historical data which
reveals an inverse relationship between obesity rates and average sleep
time, with the highest obesity percentages found in adults getting the
least amount of sleep. According to Sanjay Patel, MD, an assistant
professor of medicine at Case Western Reserve University in Cleveland,
"Sleep deprivation has important effects on a patient's health, so
clinicians should really ask their patients about their sleep habits…
Getting a good's night sleep has already been shown to have effects on
diabetes and heart disease and now we see it affects weight as well."
The optimal amount of sleep for adults recommended by The National Sleep
Foundation is seven to nine hours every night.
Obesity and Breast Cancer
There is increasing evidence that in addition to its adverse and
well-known health impact on blood pressure, diabetes, stroke, and
cholesterol levels, being overweight may also be linked to increased
rates of breast cancer in some women. This link has importance, as
obesity may be the single greatest modifiable risk factor for breast
cancer.
According to the National Cancer Institute (NCI), obese, post-menopausal women are at increased risk of dying from breast cancer. In fact, scientists estimate that about 11,000 to 18,000 deaths per year from breast cancer in U.S. women over age 50 might be avoided if women could maintain a BMI under 25 throughout their adult lives. As the NC I has noted, “weight gain during adulthood has been found to be the most consistent and strongest predictor of breast cancer risk in studies in which it has been examined.”
One recent study published in the Journal of the National Cancer Institute found that obesity and a sedentary lifestyle appear to increase the risk for an uncommon but aggressive breast cancer that is more common in younger women and African-American women. Scientists evaluated data collected on 155,723 participants enrolled in the Women’s Health Initiative, which followed postmenopausal women for 15 years starting in the early 1990s. Review of the data found that the heaviest women were 35% more likely to develop so-called triple-negative breast cancers than the thinnest women. Triple-negative breast cancers make up 10% to 20% of all cancers of the breast. They have a poorer prognosis than other tumors, in part because there are no targeted hormonal therapies to treat them. As one researcher at the University of Wisconsin notes, “These findings suggest that avoiding obesity and staying active could lower a woman’s risk for all types of breast cancer, not just those that are estrogen-receptor positive… That is a very positive message.”
A separate study by researchers in California evaluated 3,995 women with breast cancer. These researchers found that obese women have a 69 percent higher risk of dying from estrogen receptor-positive breast cancer.
At the 33rd Annual San Antonio Breast Cancer Symposium, scientists
reported a statistically significant association among women with
estrogen receptor- or progesterone receptor-positive, HER2 negative
disease. The researchers found that obese women with hormone positive,
HER2 negative breast cancer had a significantly higher risk for death
than non-obese women with the same breast cancer type. This relationship
was not found in HER2 positive or triple-negative breast cancer.
Does Vitamin D Deficiency Cause Weight Gain?
There is growing evidence that obese individuals have a deficiency in Vitamin D. In one recent study, researchers in Oslo, Norway measured vitamin D blood levels in nearly 1,800 people who were being treated for problems related to weight. Individuals who weighed the most had the lowest levels of vitamin D in their blood. It remains to be seen whether people gain weight because vitamin D levels are too low, or does being overweight cause a person's vitamin D levels to decrease?
A separate study by researchers at the University of Michigan revealed that children who were deficient in vitamin D accumulated fat around the waist and gained weight more rapidly than youngsters who got enough vitamin D. The finding of abdominal fat accumulation is especially important because this central fat can cause a so-called apple shaped body -- a body type linked to increased risks of not only type 2 diabetes but other chronic conditions later in life, including cardiovascular disease. One of the lead researchers on this study noted that "Our findings suggest that low vitamin D status may put children at risk of obesity…This is significant because vitamin D insufficiency is highly prevalent across the globe and childhood obesity rates are dramatically increasing worldwide."
While the exact relationship between vitamin D and weight gain
remains unclear, there is an increasing amount of research supporting a
link between vitamin D deficiency and being overweight.
Childhood Obesity on the Rise
Childhood obesity has reached epidemic levels in recent years.
Obesity in preschool aged children and teens has more than doubled since
the 1970`s while the obesity rate in children 6 to 11 has more than
tripled. Several reports indicate that 25 percent of children aged 2 to
5 years are overweight, and at increased risk for obesity-associated
health problems.
A study published in the New England Journal of Medicine found that
while children with pre-diabetes had nearly double the risk of dying
before 55, obesity was the factor most closely associated with an early
death, researchers said.
One recent report from the National Institute of Medicine concluded with
several recommended actions to curb high rates of obesity among
America's youngest children. Recommendations include limiting television
time, encouraging children to spend more time in physically active play,
and requiring child care providers to promote healthy sleeping
practices.
It seems clear that many children need help with their weight
management. Overweight and obese children are at risk for poor health
outcomes. Fortunately, with proper attention and guidance, many of these
children can be helped and their situation improved dramatically.
Obesity and Colon Cancer
There are approximately 150,000 new cases of colon cancer diagnosed each
year in the United States, equally split between men and women. Several
studies have found that colon cancer occurs more frequently in people
who are obese than in those of a healthy weight. One report that
evaluated over 70,000 patients found that obese individuals with a BMI
greater than 30 have a 20% greater risk of developing colorectal cancer
compared with those of normal weight (BMI less than 25). A separate
study evaluated nearly 5,000 patients and found that obese individuals
with colon cancer had a significantly poorer prognosis than non-obese
patients with colon cancer. Men in the highest BMI category for obesity
had a 35 percent increased risk of death compared to normal weight
patients. A number of mechanisms have been proposed for the adverse
effect of obesity on colon cancer risk. Many researchers now believe
that high levels of insulin or insulin-related growth factors in obese
people may promote tumor development.
Poor diet and lack of exercise are the most common attributable
sources of weight gain. In some individuals; however, medications may
contribute to their weight gain. In many of these cases, there are
alternatives available without this unwanted side effect.
Some medications associated with weight gain include diabetes
medications (ie-Humalog, Avandia, Actos, Glucotrol, Diabeta, Glynase,
Amaryl), oral steroids such as Prednisone, some antihistamines
(Benadryl), and Beta blockers (Propranolol, Metoprolol, Atenolol).
Several psychiatric and neurologic medications are also associated with
weight gain. These include some tricyclic antidepressants, SSRI’s, MAO
inhibitors, and lithium. Many ant-psychotic and anti-convulsant
medications are also linked to weight gain.
We strongly advise against stopping these medications for their effect
on your weight without talking to your prescribing physician. On the
other hand, we do encourage that you have a frank and open discussion
with your doctor about any unwanted side effects associated with a
medication. In many cases, there are alternatives to these medications
which are not associated with weight gain.
Food addiction and weight gain
The media is filled with reports of addiction to alcohol, smoking, and to illegal drugs. But addiction to food? Medically speaking, addiction can be characterized by the following traits:
- The substance is taken in larger amounts and for longer period than intended.
- There exists a persistent desire to quit.
- Significant effort will be expended to obtain the addicting substance.
- Important social, occupational, or recreational activities may be given up or reduced.
- The substance use continues despite knowledge of adverse consequences.
- The substance is associated with tolerance (marked increase in amount; marked decrease in effect).
- There are characteristic withdrawal symptoms for which the substance is taken to relieve withdrawal.
As it relates to food, addiction may be characterized by these traits below:
- Being obsessed or preoccupied with food.
- Having a lack of self-control around food.
- Having a compulsion about food leads to over-eating despite negative consequences.
- Having a sense of pleasure or comfort with food, and being unable to stop eating until this sensation is recreated
- Having a need to eat which results in a physical craving.
For many patients, these characteristics above describe their
relationship to food. It has been noted by David Kessler – former chief
of the Food and Drug Administration – that food addiction is
manufactured by an industry-wide creation of hyper-palatable foods that
induce physiological and neurologic effects similar to those created by
other addictive substances. In so far as this is the case, breaking this
addiction may require more than a little simple “will power.” Rather, a
dedicated, step-by-step plan may be required to overcome this tightly
bound, manufactured, and unhealthy relationship to food.
Do diet drinks make you hungry?
It is well-known that drinking too many sodas and sugary drinks filled with “empty calories” will lead to weight-gain. But what about “sugar-free” and “diet” drinks? One study performed by researchers at the University of Texas Health Science Center found that people who drink diet soft drinks may actually gain weight; for every can of diet soda people consumed each day, there was a 41% increased risk of being overweight. In fact, there is increasing reservoir of scientific data to support the claim that people who consume diet drinks are actually more likely to gain weight.
It appears that one reason diet drinks may lead to weight gain has to
do with their impact on signals from the brain. When we eat food, our
digestive tract signals the brain to release chemicals that make us feel
full. It seems that artificial sweeteners do not signal the brain to
release these chemicals, which means we either stay hungry or, in some
instances, may actually get hungrier. Additionally, artificial
sweeteners may negatively alter the normal balance of hormones that
affect the body's ability to maintain normal weight. This eventually
makes the body resistant to these important hormones, resulting in
reduced energy metabolism and fewer calories being burned. In effect,
diet drinks may make us eat more!
Obesity and depression
It appears that being overweight and being depressed may be linked.
One study published in the journal General Hospital Psychiatry evaluated
over 4,500 female patients, and found that women with a body mass index
(BMI) over 30 were twice as likely to be depressed than were women with
a BMI less than 30. A separate study (meta-analysis) which evaluated
results of nearly 60,000 participants found that obese persons had a 55
percent increased risk of developing depression over time, whereas
depressed persons had a 58 percent increased risk of becoming obese. The
details of how obesity and depression are linked remain unclear;
however, several hypotheses have been suggested. Some have proposed that
individuals who are overweight may be more likely to become depressed
because they experience themselves as in poor health and are
dissatisfied with their appearance. Others have suggested that
individuals who are depressed may be more likely to gain weight because
of physiological changes in their hormone and immune systems that occur
in depression. On a related note, there is evidence that weight loss may
improve mood in patients who are depressed. One study by researchers at
the University of Pennsylvania found that after a 6-month behavioral
weight loss program, depressed patients not only lost 8% of their
initial weight but also reported significant improvements in their
symptoms of depression.
Obesity, weight loss, and quality of life
It has been noted that being overweight may adversely impact an individual’s quality of life – including such items as bodily pain, physical functioning, vitality, general health, and mental health Writing over a decade ago in the journal Nutrition, researchers at Northwestern University stated, “It is clear that obesity confers negative consequences on both the physical and psychosocial aspects of quality of life, especially among the severely obese. The effects of weight loss appear to be favorable...” More recently, researchers evaluated 15 years of data (1993 – 2008) collected by the Behavioral Risk Factor Surveillance System and found that Quality-Adjusted Life Years lost to U.S. adults due to morbidity and mortality from obesity have more than doubled from 1993-2008 and the prevalence of obesity has increased 89.9 percent during the same period. A separate study of 125 overweight children found that as patients lost weight their perceived health, emotional well-being, and quality of life improved. In fact, several studies seem to support the claim that weight loss may lead to a significant improvement in an individual’s quality of life.
Weight Loss Lowers C-Reactive Protein
C-Reactive protein (CRP) is a natural protein – an “acute phase
reactant” - which serves as a marker for inflammation. Several studies
have found that patients with elevated CRP have increased rates of
diabetes, hypertension, and cardiovascular disease.
Researchers have found that CRP seems to be at least as predictive of cardiac risk as cholesterol levels. One trial - The Physicians Health Study involving 18,000 apparently healthy physicians, was the first large study to show that elevated levels of CRP were associated with a threefold increase in the risk of heart attack. In another study - the Harvard Women's Health Study - results of the CRP test were more accurate than cholesterol levels in predicting coronary problems. The relationship between a patient’s baseline level of CRP and future vascular risk has been consistent in studies from the United States and Europe. These effects are present among women as well as men, among the elderly as well as those in middle age, among smokers and non-smokers, and among those with and without diabetes.
Fortunately, it appears that CRP may decrease with weight loss. A study
conducted by researchers at the University of Vermont found that
“…caloric restriction-induced weight loss decreased plasma CRP levels.
Weight loss may represent an important intervention to reduce CRP
levels…” In a review of the weight loss literature, scientists from
Johns Hopkins University found that “Weight loss was associated with a
decline in CRP level…for each 1 kg of weight loss, the mean change in
CRP level was -0.13 mg/L.”
So it seems that weight loss may be one means to help decrease CRP – an
inflammatory marker which when elevated is associated with poor cardiac
outcomes.
Weight Loss, Diabetes, and Hemoglobin A1c Levels
Hemoglobin A1c (HgbA1C) is a form of hemoglobin in the blood which is a
marker for glucose control in patients with diabetes. The higher your
HgbA1c level, the poorer your blood sugar control. In patients with
diabetes, the higher the HgbA1c level, the higher the risk of diabetes
complications. In persons that are diabetic or pre-diabetic, the
American Diabetes Association recommends treatment including weight
loss, dietary and lifestyle modifications, and exercise. In the United
States it is estimated that over 57 million people are at risk for Type
II Diabetes, with 9 million already considered diabetic without even
knowing it. Diabetes is the number one cause for acquired blindness,
foot and leg amputations and kidney failure in the United States.
There is increasing evidence that sustainable weight loss benefits with
diabetes. One large study - the Diabetes Prevention Program – evaluated
over 3,000 participants at 27 centers around the United States. All
participants were overweight and had pre-diabetes, which are well-known
risk factors for the development of type 2 diabetes. The researchers
showed that if people at risk for type 2 diabetes lost a small amount of
weight and became more active for three years they could prevent or
delay Type 2 diabetes, and lower their blood pressure. Another large
study – the United Kingdom Prospective Diabetes Study - evaluated 5,102
patients with newly diagnosed Type 2 diabetes in 23 centers within the
U.K. The results demonstrated that the risks of complications from
diabetes can be significantly lowered with tighter glucose control as
exhibited in lower HgbA1c levels. Other studies have demonstrated that
weight loss can lead to lower the HgbA1c levels.