Although years of research have shown that obesity is a risk factor for breast cancer, for instance, just 54% of women were aware of the link, according to a recent study at the University of Texas M. D. Anderson Cancer Center in Houston.
Even fewer women knew that obesity boosts the risk of endometrial cancer. “Women who are overweight have four times the risk, probably for the same reason they’re at increased risk of breast cancer: body fat produces estrogen, a hormone that fuels these cancers,” says Pamela Soliman, MD, MPH, lead author of the study. Likewise, University of Minnesota researchers found that leptin, a hormone associated with weight gain, enhanced the proliferation of both normal and cancerous breast cells. Losing weight may help decrease the risk of both breast and endometrial cancers, as well as colorectal cancer.
Researchers at the Medical University of South Carolina in Charleston recently found that people with metabolic syndrome (a combination of high blood pressure, diabetes, and high cholesterol that’s far more common in overweight people) had a 67% higher risk of colorectal cancer than those without the problems.
2. It can make cancer treatment and recovery difficult
Not only do obese women have a higher risk of complications from breast reconstruction after mastectomy (the complication rate is close to 100% for women with a body mass index (BMI) higher than 40, M. D. Anderson researchers reported), but overweight women also appear to be less likely than normal-weight women to get the full benefit of presurgery chemotherapy, possibly because doctors (worried about drug toxicity) tend to give overweight women smaller doses of the medications than they really need. In a nutshell, “People who weigh too much are more likely than normal-weight people to die from many cancers,” Dr. Soliman says.
3. It’s hard on your heart
The fatter you are the more likely you are to have a heart attack earlier in life—12 years sooner for those who are the most obese, according to a study published in the Journal of the American College of Cardiology. One reason is that people who are overweight are more likely to have cardiac risk factors like high blood pressure, diabetes, and high cholesterol. But even after adjusting for those factors, being heavy in itself was a “considerable risk,” according to Eric Peterson, MD, an author of the study and a professor of medicine at the Duke Clinical Research Institute and Duke University Medical Center.
4. It makes exercise unappealing
Lycra tops. Itsy-bitsy running shorts. It’s no wonder obese women say self-consciousness is a major barrier to exercise. But that’s not the only thing keeping them out of the gym. “They also have more aches and pains than normal-weight women, worry they might get injured, and just feel too overweight to exercise,” says Melissa Napolitano, a clinical psychologist and associate professor of kinesiology at the Temple University Center for Obesity Research and Education, who recently surveyed 278 women of varying weights on the issue. Her advice: If you feel too self-conscious to exercise in public, find a good exercise DVD; or go to a place like Curves or the local track, where you’re more likely to see people exercising who look like you. Also, start slowly so you gradually build strength and fitness.
5. Fat is bad for your brain
Jiggly arms may be more than just a vanity issue. In a large study, researchers from the Kaiser Permanente Division of Research found that those with the fattest arms at ages 40 to 45 were 59% more likely to have dementia later in life. Another study found that obese people, particularly those with large bellies at midlife, were 260% more likely to develop dementia. “The biggest risk is the fat that hangs over your belt,” says Rachel Whitmer, PhD, lead study author. “The bigger your belly, the greater the risk for dementia, perhaps because of hormones or inflammatory factors produced by the abdominal fat itself.”
6. It doesn’t do much for your mood
Is being fat depressing or is depression fattening? Either way, there’s an association between the two, according to a recent study of 4,641 women between the ages of 40 and 65. While just 6.5% of the women who had normal BMIs were depressed, 25.9% of those with BMIs higher than 35 were. In an earlier study of more than 9,000 people across the country, researchers found a 25% increase in the risk of developing mood and anxiety disorders among those who were obese. “Obesity could contribute to depression by limiting physical activity and through the stigma associated with being overweight,” says Gregory Simon, MD, MPH, lead author of both studies and a psychiatrist at Group Health Cooperative in Seattle.
7. Fat takes a toll on joints
Arthritis cases attributed to obesity rose from 3% to 18% between 1971 and 2002, according to researchers at Beth Israel Deaconess Medical Center. “Extra weight seems to place stress on the joints, but other metabolic factors related to body fat and involving inflammation may lead to joint damage, too,” study lead author Suzanne Leveille, PhD, RN, says. “Research suggests that modest weight loss combined with exercise—even just walking five days a week—can improve arthritis symptoms.”
8. It puts pressure on your bladder
Women who are obese are twice as likely as normal-weight women to have a pelvic-floor disorder. The most common problem is urinary incontinence, according to researchers for the National Institutes of Health’s Pelvic Floor Disorders Network; others are fecal incontinence and pelvic-organ prolapse (when the uterus, bladder, small intestines, or rectum sag into the vaginal area).
“Losing even 5% to 10% of your body weight takes pressure off the pelvic floor,” says Holly Richter, PhD, MD, professor and director of the division of Women’s Pelvic Medicine and Reconstructive Surgery at the University of Alabama at Birmingham. Some other things you need to do: avoid caffeine, which can be irritating to your bladder, and do Kegel exercises.
9. It isn’t good for your other organs
Swedish researchers reported in 2006 that simply being overweight tripled the risk of chronic renal failure (CRF), a gradual, irreversible loss of kidney function. The researchers estimate that obesity causes 11% of CRF cases in women. Likewise, according to recent findings published by researchers from the Lawrence Berkeley National Laboratory in California, having a higher BMI increased the risk of gallbladder disease—even in runners.
10. Fat may produce a backlash in the bedroom
The more overweight a woman is, the more likely she is to report problems with sex, like low sexual desire, difficulty with sexual performance, and lack of enjoyment, research shows. The cause may bepoor body image. On the flip side, losing even 10% of your body weight may rekindle the flame. Says Martin Binks, PhD, research director at the Duke Diet and Fitness Center: “We saw dramatic reductions in the number of people reporting sexual difficulty following moderate weight loss—and the most significant improvement was seen during the first three months.”
11. It makes some medical tests tricky
According to a 2008 study in Obesity, just 10% of hospitals with emergency departments had computed tomography (CT) scan machines capable of accommodating very obese people, and even fewer had magnetic resonance imaging (MRI) machines that could. “Blood pressure cuffs, paper robes, wheelchairs, and gurneys are less likely to be options for people who are obese,” says Deborah Carr, PhD, an associate professor of sociology at Rutgers University in New Brunswick, New Jersey.
12. It may affect your medical care
Some doctors associate obesity with unpleasant character traits, like hostility, dishonesty, and poor hygiene, research has shown. In fact, in a survey of nearly 2,500 overweight and obese women, 69% said they’d been on the receiving end of a doctor’s bias. The result, according to a 2008 report from the Yale University Rudd Center for Food Policy and Obesity, is that doctors spend less time with overweight patients and are even reluctant to perform preventive screenings and exams.
13. It can interfere with your fertility
Obesity accounts for 6% of infertility cases in women, the American Society for Reproductive Medicine says. Why? Too much body fat may produce too much estrogen, which can suppress ovulation. In one study, the probability of getting pregnant declined in women with BMIs higher than 29—and for every one-point increase in BMI, there was a 4% lower pregnancy rate. (Can’t get pregnant? Try acupuncture.)
In other research, obese women had high levels of fats and inflammation in the fluid surrounding their eggs, an environment that could affect an egg’s developmental potential. Even a 5- to 10-% weight loss may dramatically improve pregnancy rates, but it’s important to establish and maintain a healthy weight before trying to conceive.
14. It makes pregnancy riskier
Overweight and obese women are more likely to have gestational diabetes, preeclampsia, and cesarean sections—all of which pose risks to mom and baby. They’re also 67% more likely to have a miscarriage than normal-weight women, researchers in the United Kingdom say.
15. It may even affect your baby’s health
In a study of nearly 15,000 mothers, more than 10,000 of whom had babies with birth defects, Kim Waller, PhD, associate professor of epidemiology at the University of Texas at Houston School of Public Health, and her colleagues found that obesity was associated with seven birth defects, including spina bifida, heart defects, shortened limbs, and hernias.
16. It may make asthma harder to treat
Several studies have linked the risk of asthma with the numbers on the scale. Researchers at National Jewish Health in Denver reported that glucocorticoids (one of the key meds to control wheezing) were 40% less effective in overweight and obese asthma patients than in those of normal weight.
17. It keeps you up at night
“Obesity is the most significant risk factor for sleep apnea,” Popkin says. Extra body fat in the chest and neck can restrict air passages and even lung function, contributing to dozens of mini-arousals to help you catch your breath. Sleep apnea causes more than just fatigue: “It’s also linked with heart disease,” he says. (Do you have sleep apnea? Read up on the risk factors.)
18. It makes you less likely to be hired
Obese job applicants are rated more negatively and are less likely to be hired than others with the same qualifications, according to the 2008 Rudd Center report. Also, a 2007 study of more than 2,800 people in the United States found that overweight adults were 12 times more likely to report weight-based employment discrimination; obese people, 37% more likely. Women are particularly likely to suffer.
19. It can affect your bottom line
Not only do overweight people tend to earn less than normal-weight people holding comparable jobs, but when they suffer from the diseases they’re at greater risk for they’re also likely to pay more for health care.
For example: The total spending on drugs for type 2 diabetes nearly doubled between 2001 and 2007, says Caleb Alexander, an assistant professor of medicine at the University of Chicago and the lead author of a study on the topic.
Because newer meds tend to be more expensive but not always more effective, Alexander suggests that people with type 2 diabetes ask their doctors to consider older, less expensive alternatives. Even cheaper: “Some patients can control diabetes with lifestyle changes alone,” he says. “At the very least, weight loss through diet and exercise can often reduce the number of medications you need to take.”