'Healthy Obesity' Is a Myth, Report Says
Researchers
weigh results of 8 studies, find excess pounds raise death risk over time
WebMD News from HealthDay
By Steven Reinberg
HealthDay Reporter
MONDAY, Dec. 2, 2013
(HealthDay News) -- The notion that some people can be overweight or obese and
still remain healthy is a myth, according to a new Canadian study.
Even without high blood
pressure, diabetes
or other metabolic issues, overweight and obese people have higher rates of
death, heart attack
and stroke after 10 years
compared with their thinner counterparts, the researchers found.
"These data suggest
that increased body weight is not a benign condition, even in the absence of
metabolic abnormalities, and argue against the concept of healthy obesity or
benign obesity," said researcher Dr. Ravi Retnakaran, an associate professor
of medicine at the University of Toronto.
The terms healthy obesity
and benign obesity have been used to describe people who are obese but don't
have the abnormalities that typically accompany obesity, such as high blood
pressure, high blood sugar and high cholesterol, Retnakaran explained.
"We found that
metabolically healthy obese individuals are indeed at increased risk for death
and cardiovascular events over the long term as compared with metabolically
healthy normal-weight individuals," he added.
It's possible that obese
people who appear metabolically healthy have low levels of some risk factors
that worsen over time, the researchers suggest in the report, published online
Dec. 3 in the Annals of Internal Medicine.
Dr. David Katz, director of
the Yale University Prevention Research Center, welcomed the report.
"Given the recent attention to the 'obesity paradox' in the professional
literature and pop culture alike, this is a very timely and important paper,"
Katz said. (The obesity paradox holds that certain people benefit from chronic
obesity.)
Some obese people appear
healthy because not all weight gain is harmful, Katz said. "It depends
partly on genes, partly on the source of calories, partly on activity levels, partly
on hormone levels. Weight gain in the lower extremities among younger women
tends to be metabolically harmless; weight gain as fat in the liver can be
harmful at very low levels," Katz said.
A number of things,
however, work to increase the risk of heart attack, stroke and death over time,
he added.
"In particular, fat in
the liver interferes with its function and insulin sensitivity," Katz
said. This starts a domino effect, he explained. "Insensitivity to insulin
causes the pancreas to compensate by raising insulin output. Higher insulin
levels affect other hormones in a cascade that causes inflammation.
Fight-or-flight hormones are affected, raising blood pressure. Liver
dysfunction also impairs blood cholesterol levels," Katz said.
In general the things
people do to make themselves fitter and healthier tend to make them less fat,
he added.
"Lifestyle practices
conducive to weight control over the long term are generally conducive to
better overall health as well. I favor a focus on finding health over a focus
on losing weight," Katz noted.
For the study,
Retnakaran's team reviewed eight studies that looked at differences between
obese or overweight people and slimmer people in terms of their health and risk
for heart attack, stroke and death. These studies included more than 61,000
people overall.
In studies with follow-ups
of a decade or more, those who were overweight or obese but didn't have high
blood pressure, heart disease or diabetes still had a 24 percent increased risk
for heart attack, stroke and death over 10 years or more, compared with
normal-weight people, the researchers found.
Greater risk for heart
attack, stroke and death was seen among all those with metabolic disease (such
as high cholesterol and high blood sugar) regardless of weight, the researchers
noted.
As a result, doctors should
consider both body mass and metabolic tests when evaluating someone's health
risks, the researchers concluded.
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