Good fat: How being overweight can work to your advantage
If obesity is so bad, why do fat heart patients survive longer than their normal-weight counterparts?
Although obesity has been linked to a variety of health problems, such as hypertension, diabetes mellitus, renal disease, stroke and heart disease, a growing body of research is finding that obese people with those diseases actually live longer than normal-weight patients who are similarly afflicted.
It's called the “obesity paradox,” and while it has some doctors scratching their heads, experts point out that the paradox doesn't mean folks with heart problems should let themselves get fat. Instead, they say, the studies show it's time to approach the problem of obesity from a different angle.
Traditionally, obese people with health problems have been assumed to have lower life expectancy, which leads to dramatically higher life insurance quotes.
Thin people don’t do so well after heart attacks
A 2010 study by the University of Rochester School of Medicine and Dentistry found that among patients who had already suffered a heart attack, non-obese people had a 76 percent increased risk of dying suddenly from cardiac causes than obese patients.
Dr. Ilan Goldenberg, a research associate professor who worked on the study, says the research focused on patients -- from slender to obese -- who had heart attacks resulting in reduced blood-pumping capability.
"In this specific population, we have identified a 'paradoxical' effect of obesity that results in patients with higher body mass index [in the obese range] having a lower risk of sudden cardiac death," he says. "Patients who are overweight have a better outcome, possibly due to the fact that they are able to handle the heart failure symptoms better than patients who have a normal weight."
The same unexpected result occurred when doctors looked at the effects of cigarette smoking, Goldenberg says. Smoking increases the risk for a first heart attack in young patients but seems to reduce the risk of subsequent heart attacks. Yet smoking, like obesity, is used as trigger for high life insurance rates.
Dr. George Griffing, a professor of medicine at St. Louis University, says medical trials looking at patients with congestive heart failure also found that obesity didn't worsen the condition and that obese patients with congestive heart failure lived longer than their slimmer counterparts with the disease.
What’s up with this?
Griffing said there could be several reasons why obese heart patients do better than slimmer patients.
One theory is that when obese patients get to a hospital they are often treated more aggressively than normal-weight heart patients because doctors think there is a greater urgency in their situations. Griffing says it may also be that obese people show signs of heart trouble sooner and thus seek treatment sooner. And finally, it could be that fat tissue secretes a kind of protective hormone.
Goldenberg and fellow researcher Eric Hansen say it could be that an obese person's body is already accustomed to surviving difficult conditions because obese people often don't eat right or exercise, and many also smoke.
"Perhaps [obese patients] are better equipped, from a genetic standpoint, to live with heart failure," Hansen said in a statement released with the March 2010 study.
Goldenberg notes that researchers at Rochester did not look at whether the heart attack patients in the study ever did any exercise. He said the patients' lack of exercise and their unhealthy habits may have been what brought on their heart attack in the first place. And staying fat after the heart attack, while improving their chances when compared to thinner patients, wouldn't be as good for them as starting to do some exercise and intentionally losing weight.
"Probably their risk will be reduced," he says.
Calculating your body fat
Your body mass index (BMI) is a measure of body fat based on height and weight. There are a number of online BMI calculators, including one from the National Institutes of Health (NIH). According to the NIH, a normal weight is from 18.5 to 24.9 BMI. A BMI between 25 and 29.9 is considered overweight, and anything over 30 is considered obese.
Many Americans score in the higher range. The Centers for Disease Control call obesity an epidemic in the United States, with two-thirds of Americans considered obese or overweight.
And with thousands of doctors around the country urging their patients to lose weight due of a high BMI, Griffing, the editor-in-chief for internal medicine at eMedicine, is urging doctors to screen their patients another way. Griffing says the obesity paradox exists because body mass index is not the best method for determining which patients have the kind of "bad" fat that worsens a cardiac condition.
"I have patients who are 500 pounds and they have normal blood pressure," he says. "BMI is based on height and weight and it's not a good way of looking at metabolically dangerous obesity. Not all fat is bad fat. The bad fat is the excess fat that gets stored around your organs, and BMI doesn't necessary tell you how much of that you have."
Griffing advocates using abdominal height as a way of determining how much "bad fat" -- the kind that is tucked into body fissures and crowds vital organs -- a person has. Abdominal height is simply a measurement of how high a patient's stomach sticks up in the air when they are laying flat on an examination table.
Abdominal height is better than other measurements -- including BMI, skin-fold thickness and waist-hip ratios -- because it measures intra-abdominal fat and signals a number of potential problems, from heart disease to impotence to liver and pulmonary problems, Griffing says.
"When your patient's belly enters your office before they do, think about getting out that ruler and measuring abdominal height," Griffing advises. "Unfortunately, for many of my patients that ruler has to be a yardstick."
More research needed
Goldenberg says he thinks the study of 1,231 patients he worked on with medical students Hansen and Bonnie Choy needs more investigation.
"Why do obese heart failure patients see a risk advantage? Why do normal weight patients have a significantly different risk profile than those who are slightly overweight? These are important questions that may have treatment implications in the future," Goldenberg says.
Read more about the most expensive medical conditions for life insurance shoppers.