|Vast Majority of Adults at Risk of Becoming Overweight or
Future burden of obesity-related conditions likely to be substantial, warn
A large, community-based study — considered the first study to assess
the long-term risk of developing overweight and obesity in adults — found
that over 30 years, nine out of 10 men and seven out of 10 women were overweight
or became overweight. In addition, more than one in three were obese or became
obese. The study was supported by the National Heart, Lung, and Blood Institute
(NHLBI), one of the National Institutes of Health (NIH).
Researchers analyzed the short-term and long-term chances of developing overweight
and obesity among more than 4,000 white adults enrolled in the offspring cohort
of NHLBI's landmark Framingham Heart Study, an ongoing longitudinal study in
Framingham, Massachusetts. Participants ages 30 to 59 were followed for 30 years,
from 1971 to 2001. The results appear in the October 4, 2005, issue of the Annals
of Internal Medicine.
“National surveys and other studies have told us that the United States has
a major weight problem, but this study suggests that we could have an even more
serious degree of overweight and obesity over the next few decades,” said NHLBI
Director Elizabeth G. Nabel, M.D., who also co-chairs the NIH Obesity Research
Task Force. “In addition, these results may underestimate the risk for some ethnic
Framingham participants were white, and other studies have shown, for example,
that Hispanic and black individuals, especially women, have a greater prevalence
of excess weight compared to their white counterparts.
According to the National Center for Health Statistics, part of the Centers
for Disease Control and Prevention, 65 percent of U.S. adults aged 20 years and
older are either overweight or obese, and approximately 30 percent of adults
are obese. These estimates are from the 1999-2002 National Health and Nutrition
Examination Survey, a population-based survey.
Framingham researchers assessed the participants’ body mass index (BMI) — a
standard measure of weight relative to height, which is an indicator of total
body fat. A BMI of 18.5 to 24.9 kg/m2 is considered a normal, or healthy,
weight for adults. Overweight is a BMI of 25 to 29.9 kg/m2, and obesity
is a BMI of 30 kg/m2 or higher.
Making it to middle age without extra pounds was no guarantee for staying at
a healthy weight — even in the short term. About one in five women and
one in four men who were at a healthy BMI at a routine Framingham study examination
became overweight after four years. Among those who were overweight, 16 to 23
percent of women and 12 to 13 percent of men became obese within four years.
“Our results, although not surprising, are worrisome,” comments Ramachandran
Vasan, M.D., Associate Professor of Medicine at Boston University School of Medicine
and lead author of the study. “If the trend continues, our country will continue
to face substantial health problems related to excess weight.”
“Overweight and obesity increase the risk of poor health. We hope these results
will serve as a wake-up call to Americans of all ages,” adds Nabel. “Even those
who are now at a healthy weight need to be careful about maintaining energy balance
to avoid gaining weight. Taking simple steps to make sure that the overall the
number of calories you consume do not exceed the amount you burn can play a major
role in lowering your risk for many chronic conditions.”
Overweight increases the likelihood of developing diabetes, high blood pressure
and heart disease, stroke, breathing problems such as asthma and sleep apnea,
some cancers, osteoarthritis, and gall bladder disease. Obesity is associated
with these conditions as well as with early death. Research has shown that even
a small weight loss (just 10 percent of body weight) can help people who are
overweight or obese lower their risk of developing many of these conditions.
The Clinical Guidelines on the Identification, Evaluation, and Treatment
of Overweight and Obesity in Adults recommend that both people who are
overweight as well as those who are at a healthy weight prevent weight gain.
The guidelines are available online at http://www.nhlbi.nih.gov/guidelines/obesity/ob_home.htm.
Strategies that promote a healthy weight beginning in childhood are critical.
For information on We Can!, NIH’s national education program to enhance children’s
activity and nutrition to prevent childhood obesity, visit the website at http://wecan.nhlbi.nih.gov or
call toll-free 866-35-WECAN.
For help assessing obesity risk and advice on how to lose weight, consult your
To interview a scientist about this study, contact the NHLBI Communications
Office at (301) 496-4236.
NHLBI is part of the National Institutes of Health (NIH), the Federal Government’s
primary agency for biomedical and behavioral research. NIH is a component of
the U.S. Department of Health and Human Services. NHLBI press releases and
other materials including information about obesity prevention and weight loss
are available online at www.nhlbi.nih.gov.
The National Institutes of Health (NIH) — The Nation's Medical Research
Agency — includes 27 Institutes and Centers and is a component of
the U. S. Department of Health and Human Services. It is the primary Federal
agency for conducting and supporting basic, clinical, and translational medical
research, and it investigates the causes, treatments, and cures for both common
and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov.