'Healthy Obesity' Is a Myth, Report Says
Researchers weigh results of 8 studies, find excess pounds raise death risk over time
Monday, December 2, 2013
videoMONDAY, 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.
SOURCES: Ravi Retnakaran M.D., associate professor, department of
medicine, University of Toronto, Canada; David Katz, M.D., M.P.H.,
director, Yale University Prevention Research Center, New Haven, Conn.;
Dec. 3, 2013, Annals of Internal Medicine, online
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