PA) - According to a study that appears in the November 17 issue
of The New England Journal of Medicine, researchers at
the University of Pennsylvania School of Medicine
found that weight loss medications work best when combined with
dieters' own efforts to modify their eating and exercise habits.
Study participants who received combined therapy lost significantly
more weight than all other groups.
"Weight loss medications helped people lose weight, as did
a program of lifestyle modification designed to improve eating and
exercise habits. However, we found that a combination of the two
approaches produced approximately twice the weight loss of either
intervention used alone," reported Thomas A. Wadden,
Ph.D., lead author of the paper and director of the Weight
and Eating Disorders Program at Penn. The research was supported
by the National Institute of Diabetes and Digestive and Kidney Disease,
one of the National Institutes of Health.
The one-year study examined 180 women and 44 men with an average
age of 44 years, weight of 235 lb., and body mass index of 37.7
kg/m2. Participants were randomly assigned to one of four treatment
groups, all of which were instructed to consume 1200-1500 calories
a day and to exercise 30 minutes a day, most days of the week.
Participants in the first group were prescribed 10-15 mg/d of the
weight loss medication sibutramine (MERIDIA™, Abbott Laboratories)
and had 8 brief (10-15 min) visits during the year with a primary
care practitioner. These individuals received minimal instruction
in lifestyle modification, consistent with the manner in which most
physicians prescribe weight loss medications.
Individuals in the second group received group lifestyle modification
alone, which is recommended as the first step of treatment for all
overweight and obese individuals. They attended a total of 30 group
sessions (90 minutes each) over the year and were instructed to
keep daily records of their food intake and physical activity which
were reviewed during the sessions.
Participants in the third group received a combination of the first
two approaches (i.e., sibutramine plus group lifestyle modification)
to determine whether the combined therapy would be superior to either
approach used alone.
Individuals in the fourth group received sibutramine and met with
a primary care practitioner 8 times during the year, and were also
encouraged to keep daily food and activity records. This group was
included to see if practitioners could provide effective lifestyle
modification counseling during brief visits.
At the end of 1 year, participants in the four groups lost 11.0
lb (sibutramine alone), 14.7 lb (group lifestyle modification alone),
26.6 lb (combined therapy), and 16.5 lb (sibutramine plus brief
lifestyle counseling), respectively. Participants who received combined
therapy lost significantly more weight than those in the three other
"These findings clearly indicate that weight loss medications
are most effective when combined with a comprehensive program of
lifestyle modification," said Robert Berkowitz, M.D.,
a co-author of the study and Associate Professor of Psychiatry at
Penn. "Sibutramine appears to modify internal signals that
control hunger and fullness, while lifestyle modification teaches
individuals to control the external food environment - for example,
by keeping food records or shopping for groceries from a list,"
added Berkowitz, who is also Chair of Psychiatry, The Children's
Hospital of Philadelphia. Participants who received sibutramine
plus brief lifestyle counseling lost significantly more weight than
those treated by sibutramine alone during the first 18 weeks (18.7
vs 13.6 lb, respectively), suggesting that primary care providers
can provide effective lifestyle counseling during routine office
Examining all 224 participants, weight loss at the end of the year
was associated with a 14.7% reduction in triglyceride levels and
an 18.9% decrease in insulin resistance, a condition that usually
precedes the development of type 2 diabetes. Larger weight losses
were associated with greater improvements in these measures, as
well as with greater improvements in high-density-lipoprotein cholesterol
(i.e., the "good" cholesterol).
"Our findings indicate that weight loss medications should
be used only as an adjunct to a program of lifestyle modification,
as recommended by both the National Institutes of Health and the
Food and Drug Administration," said Wadden. "Lifestyle
modification can begin with efforts to reduce portion sizes, keep
a daily food log, and increase daily walking. The more approaches
you combine, the less you'll weigh," he added.
PENN Medicine is a $2.7 billion enterprise
dedicated to the related missions of medical education, biomedical
research, and high-quality patient care. PENN Medicine consists
of the University of Pennsylvania School of Medicine (founded in
1765 as the nation's first medical school) and the University of
Pennsylvania Health System.
Penn’s School of Medicine is ranked #2 in the nation
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research-oriented medical schools. Supporting 1,400 fulltime faculty
and 700 students, the School of Medicine is recognized worldwide
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The University of Pennsylvania Health System comprises: its
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consistently rated one of the nation’s “Honor Roll”
hospitals by U.S. News & World Report; Pennsylvania Hospital,
the nation's first hospital; Penn Presbyterian Medical Center; a
faculty practice plan; a primary-care provider network; two multispecialty
satellite facilities; and home health care and hospice.