Blanck HM, Khan LK, Serdula MK. Use of Nonprescription Weight Loss ProductsResults From a Multistate Survey. JAMA. 2001;286(8):930–935. doi:10.1001/jama.286.8.930
Author Affiliations: Division of Nutrition and Physical Activity, National Center for Chronic Disease Prevention and Health Promotion (Drs Blanck, Khan, and Serdula), and Epidemic Intelligence Service, Division of Applied Public Health Training, Epidemiology Program Office (Dr Blanck), Centers for Disease Control and Prevention, Atlanta, Ga.
Context Lifestyle changes to lose weight can be difficult; hence, both prescription
and nonprescription diet products are appealing. Usage patterns of the nonprescription
products phenylpropanolamine (PPA) and ephedra are of particular interest
because of recent safety concerns.
Objective To estimate the prevalence of overall and specific nonprescription weight
loss product use by demographic characteristics, prescription diet pill use,
diabetic status, and lifestyle choices.
Design and Setting The Behavioral Risk Factor Surveillance System, a random-digit telephone
survey conducted in 1998 in 5 states: Florida, Iowa, Michigan, West Virginia,
Participants Population-based sample of 14 679 noninstitutionalized adults 18
years or older.
Main Outcome Measures Prevalence of nonprescription weight loss product use in 1996-1998.
Results Seven percent reported overall nonprescription weight loss product use,
2% reported PPA use, and 1% reported ephedra product use. Overall use was
especially common among young obese women (28.4%). Moreover, 7.9% of normal-weight
women reported use. There was no difference in nonprescription weight loss
product use by daily consumption of fruits and vegetables; however, more users
than nonusers reported being physically active (for those who exercised ≥30
minutes 5 times per week, odds ratio, 1.5; 95% confidence interval, 1.2-2.0).
Among prescription weight loss product users, 33.8% also took nonprescription
Conclusions With increasing rates of obesity, nonprescription product use is likely
to increase. Clinicians should know about their patients' use of both prescription
and nonprescription weight loss products.
Successful weight loss and healthy weight management depend on long-term
lifestyle changes such as reducing calorie consumption and increasing physical
activity. However, because these changes are difficult, easily obtained nonprescription
weight loss products and prescription diet pills are an appealing alternative
to the increasingly overweight US population. It has been speculated that
individuals may use nonprescription products and prescription pills in place
of lifestyle changes.1 No population-based
studies have examined the relationship between use of overall nonprescription
weight loss products and use of prescription weight loss pills or lifestyle
changes for weight loss. Usage patterns of specific nonprescription products
(eg, phenylpropanolamine [PPA] and ephedra) are also of particular interest
because of safety concerns.
Ephedra products have stimulant properties and are purported to decrease
weight when used in combination with caffeine through thermogenesis and reduced
appetite.2- 4 In
June 1997, the Food and Drug Administration (FDA) proposed restrictions on
dietary supplements containing ephedrine alkaloids.5
However, this proposal was withdrawn in April 2000 after the General Accounting
Office concluded that additional evidence was needed to support these restrictions.6 Although the FDA withdrew certain provisions of the
ephedrine alkaloids proposal, the agency remains concerned and is continuing
to passively monitor adverse events associated with the use of these products.6 Because of potential adverse health effects among
persons with diabetes, hypertension, heart disease, and other conditions,
the FDA has recommended a labeling statement that instructs ephedra users
to seek the advice of a health care provider before use.5
Phenylpropanolamine, the main ingredient in the over-the-counter (OTC)
weight loss aids Dexatrim and Acutrim, is a synthetic ephedrine alkaloid with
stimulant properties that may reduce appetite.7
Until recently, PPA was considered to be a safe short-term weight reduction
agent8; however, case reports of adverse cerebrovascular
and cardiac events9- 11
and a study in which PPA increased the risk of stroke12
resulted in the voluntary withdrawal of all OTC PPA products from the market
in November 2000.13
To assess who uses nonprescription weight loss products in the United
States, 5 states incorporated questions that asked about overall and specific
nonprescription weight loss product use during the previous 2 years into their
1998 Behavioral Risk Factor Surveillance System (BRFSS) surveys. We used these
data to examine the prevalence of overall and specific nonprescription product
use by demographic characteristics, lifestyle choices, prescription pill use,
and presence of diabetes.
The data come from adults 18 years or older who participated in the
1998 BRFSS in Florida, Iowa, Michigan, West Virginia, and Wisconsin. The BRFSS
is a random-digit telephone survey, conducted by state health departments,
that assesses individual health practices. (For a detailed description of
the survey methods and quality control indexes, see Nelson et al.14) The average cooperation rate (completed interviews/refusals
+ terminations + completed interviews) for the 5 states was 67.5% (range,
Respondents were first prompted by the following statement: "Now we
would like you to tell us about any over-the-counter products such as pills,
powders, or liquids, you have taken to lose weight. That is, products you
do not need a prescription to purchase." Respondents were then asked, "In
the past 2 years, have you taken any over-the-counter weight loss products?"
If respondents replied positively, they were then asked, "Have you taken any
of the following over-the-counter weight loss products in the past 2 years.
Herbal fen-phen (also known as natural fen-phen, or fen-fuel)? Acutrim or
Dexatrim? Ma-huang? St. John's wort? Ephedra? Or other?" Respondents were
prompted for each category and responses recorded as "yes," "no," "don't know,"
or "refused." A positive response to herbal fen-phen, ma-huang, or ephedra
was used to classify an individual as an "ephedra product" user in our analyses.
One state (Michigan) asked the respondent to specify the product name or type
when an "other" nonprescription product was taken.
Respondents were asked to report their current height and weight without
shoes. Each respondent's body mass index (BMI) was calculated as weight in
kilograms divided by height in meters squared. (The BMI was categorized as
<25, normal weight; 25-29.9, overweight; ≥30, obesity.) Respondents
were asked for information on age, race/ethnicity, education, current smoking
status (current, former, never), current weight loss practices (whether they
were currently trying to lose or maintain weight), diabetic status ("Have
you ever been told by a doctor that you have diabetes?"), and usual daily
fruit and vegetable consumption (how often they drank fruit juices and how
often they ate fruit, green salad, potatoes, carrots, or other vegetables).
Respondents were also asked about the frequency and duration in the previous
month of their 2 most frequent leisure-time physical activities. Both physical
activity and fruit and vegetable questions were used to determine whether
respondents were meeting national recommendations of 5 or more servings of
fruits and vegetables per day and 30 minutes or more of physical activity
5 or more times per week.15 Respondents were
also asked about any prescription weight loss product use in the past 2 years
by the following question, "In the past 2 years, have you taken any weight
loss pill prescribed by a doctor? Do not include water pills or thyroid medications."
We excluded all respondents for whom certain data were missing: weight,
height, or weight loss status (n = 411) and sociodemographic factors (n =
95). We also excluded all pregnant women (n = 177). Three respondents were
excluded because they reported weight, height, or BMI outside the minimum
and maximum reference values of measured weight, height, and BMI by sex from
the Third National Health and Nutrition Examination Survey (NHANES III), 1988-1994.16 We believe these outliers were due to either erroneous
reporting or data entry errors. The final analytical sample was 14 679.
The BRFSS uses a stratified random sample approach and the data are
weighted for age, race, and sex prior to data analysis. This weighting allows
for inference to the state population. To account for the complex sampling
design, we used SUDAAN for the primary analysis.17
We used logistic regression to assess the association between use of nonprescription
weight loss products (both overall and specific use) and demographic characteristics
(sex, age [18-34 years, 35-54 years, ≥55 years], race/ethnicity), current
BMI (normal weight, overweight, obese), prescription weight loss pill use
in the past 2 years (yes or no), and lifestyle characteristics including current
smoking status (current vs former or never), usual daily fruit and vegetable
consumption (<1, 1-2, 3-4, ≥5 times per day), and physical activity
(inactive, somewhat active, met the physical activity recommendation). Biologically
relevant 2-way interaction terms were evaluated, eg, BMI × age, BMI
× sex. None of the interaction terms assessed were significantly associated
with overall nonprescription product use or specific nonprescription product
use at the α = .05 level. No collinearity was observed. Odds ratios
and accompanying 95% confidence intervals were obtained from the RLOGISTIC
procedure in SUDAAN.
More than half of the respondents were women (Table 1). The majority of all respondents were non-Hispanic white.
Slightly more than half had at least some college education and most were
older than 35 years. Less than half of the participants were normal weight,
one third were overweight, and one fifth were obese. Approximately one third
reported they were currently trying to lose weight, and one third reported
they were currently trying to maintain weight.
Seven percent of the respondents reported using at least 1 nonprescription
weight loss product during the previous 2 years (Table 2). Women and younger adults were significantly more likely
to be users, whereas there was no difference in use by ethnicity. People with
at least a high school diploma were also more likely to report using nonprescription
products than those with less education. Nonprescription product use increased
significantly with increasing BMI. Nonprescription product use was common
among obese women of all ethnic groups 18 to 34 years of age (28.4%): non-Hispanic
white, 30.3%; non-Hispanic black, 26.1%; and Hispanic, 27.1%. Nonprescription
product use was also common among those who reported they were trying to lose
weight (14.3%; SE, 0.6%) and less common among those trying to maintain their
current weight (3.6%; SE, 0.4%). We found that some respondents who at the
time of the survey were not overweight or obese also reported taking nonprescription
products in the past 2 years (overall, 5.1%; women, 7.9%; men, 0.8%).
Of those who took any prescription weight loss product in the previous
2 years, over one third reported also using nonprescription products. In relation
to lifestyle choices, there was no consistent difference in nonprescription
product use by daily fruit and vegetable consumption; however, those who reported
at least some physical activity were more likely than inactive respondents
to report using nonprescription products.
We also assessed the prevalence of specific types of nonprescription
weight loss products, specifically ephedra and PPA products, by select demographic
characteristics and lifestyle choices (Table 3). We found that 1% of respondents used ephedra products
and 2% used PPA. Multivariate logistic regression results for specific nonprescription
product use were generally similar to those for overall nonprescription product
use, but the magnitude of the association measure differed for some relationships.
For example, women were almost 9 times more likely than men to report use
of a PPA weight loss product and prescription pill users were 9 times more
likely than nonusers to have also taken ephedra products.
Because of possible safety issues, we also assessed use of nonprescription
products among persons who reported physician-diagnosed diabetes. Among the
people with diabetes, 5.9% (SE, 1.2%) reported having used any nonprescription
weight loss product, 1.2% (SE, 0.5%) used PPA, and 0.6% (SE, 0.4%) used an
ephedra product compared with 7.0% (SE, 0.3%), 2.1% (SE, 0.2%), and 1.0% (SE,
0.1%) of people without diabetes, respectively.
Of the 183 respondents in Michigan who reported "other" nonprescription
product use, 58% reported using liquid meal-replacement products (eg, Slim
Fast and Sweet Success), 33% reported using name-brand products that claim
to contain both ephedra products and chromium picolinate, and 6% reported
using products claiming to contain chromium picolinate without ephedra. An
additional 3% of respondents could not remember the name of the product(s).
In this population-based study of US adults in 5 states, 7% reported
using nonprescription weight loss products, 2% reported using PPA, and 1%
reported using ephedra products from 1996 to 1998. Extrapolated nationally,
we estimate that during 1996 through 1998, approximately 17.2 million Americans
used nonprescription weight loss products, 5.0 million used PPA, and 2.5 million
used products containing ephedra. Overall use was common among women, especially
young obese women, over one quarter of whom reported use. Moreover, 8% of
normal-weight women reported nonprescription product use.
Our data are generally supported by a 1991 nationally representative
study of persons trying to lose weight. Leavy and Heaton18
found that 20% of women and 11% of men reported using a weight control product
(including weight loss pills, diet supplements, and laxatives). In our study,
18% of women and 8% of men who were currently trying to lose weight reported
using nonprescription weight loss products. Although our data included liquid
or powder meal-replacement products, we did not have specific information
on the use of diuretics or laxatives.
Recently, questions were raised regarding the safety of PPA and ephedra.
Between June 1997 and March 1999, the FDA received 140 reports of adverse
events among users of ephedra products.19,20
Ephedra products are regulated as dietary supplements under the 1994 Dietary
Supplement Health and Education Act.21 Dietary
supplements are generally regarded as safe and are regulated as foods rather
than drugs. Under the Dietary Supplement Health and Education Act, the burden
of proof for establishing that dietary supplements are unsafe falls to the
FDA rather than to the manufacturer.21,22
In addition, the FDA is not responsible for quality control, which means that
there can be a discrepancy between the actual composition or potency of a
product and the specifications on the label. For example, 11 of 20 ephedra
supplements tested failed to list the ephedrine alkaloid content on the label
or had more than a 20% difference between the actual amount and the amount
listed on the label.23
As a synthetic ephedrine alkaloid, PPA is not regulated as a dietary
supplement but as an OTC drug. In November 2000, the FDA's Nonprescription
Drugs Advisory Committee concluded that PPA was associated with hemorrhagic
stroke and recommended that PPA not be considered safe for OTC use. The committee
recommended removal of all OTC PPA products from the market.13
This withdrawal left future use of PPA products uncertain and may increase
sales of other weight loss products such as prescription drugs, ephedra products,
and other dietary supplements.
Health care professionals need to know about their patients' use of
both prescription and nonprescription weight loss products. In our study,
over one third of women users of prescription pills and one tenth of men users
also reported taking nonprescription products at some time during the 2-year
time period. In fact, prescription pill users were 9 times more likely than
nonusers to have also taken ephedra products in the 2-year period and twice
as likely to have taken PPA products. Our survey did not collect information
as to whether the products were taken serially or simultaneously; the dose,
duration, or frequency; prior use of these products; or whether users of nonprescription
weight loss products told their physicians. It is important for physicians
to know if multiple weight loss products are being taken at the same time,
as there is a possibility for herb-drug and drug-drug interactions.
Dietary supplements and alternative therapies are a particular challenge
for physicians. Many patients do not inform their physicians about their use
of these products.24 Of particular concern
was our finding that ephedra and PPA were used by people with diabetes. In
this group of individuals, use of these products may result in adverse effects,5,9,25 especially if uncontrolled
hypertension is present. We did not have data for nonprescription weight loss
product use in persons who have other weight-related health conditions such
as hypertension and heart disease. Use of ephedra and PPA products may put
these individuals at risk for adverse health events such as myocardial infarction
We found little evidence to support the speculation that nonprescription
product users are less likely to change their lifestyle compared with nonusers.
There was no difference in nonprescription product use by fruit and vegetable
consumption, but nonprescription product users were less likely to be sedentary
than non-nonprescription product users. However, the proportion meeting the
national recommendations for physical activity was similar for both groups.
Our analysis is limited in that respondents were asked about any use of nonprescription
and prescription weight loss products in the past 2 years, whereas they were
asked about current weight and height, usual fruit and vegetable consumption,
and previous month leisure-time physical activity.
We were not able to verify the actual product(s) taken from the BRFSS.
There are 2 potential effects on our prevalence estimates that cannot be confirmed.
Some respondents may have not been aware that they were taking ephedra products
and thus underreported their intakes. To the contrary, it is also possible
that some respondents took an herbal fen-phenlike product that did not contain
ephedra and thus overreported ephedra use.
Since obesity is a chronic disease it is possible that individuals may
use nonprescription products to maintain weight loss; however, use of these
products by normal-weight individuals could expose them to risks for which
there are no counterbalancing benefits. Our survey did not collect information
on whether the respondent experienced adverse effects from the nonprescription
product or whether weight loss or weight maintenance was achieved. Although
respondents were asked about whether they were currently trying to lose or
maintain weight, they were not asked about the current type of diet or current
weight loss product they were taking.
Providing appropriate science-based advice will be a challenge for health
care professionals because of the increasing variety of nonprescription products
on the market and the lack of methodologically sound efficacy studies.1,26 The continuing increase in the rate
of obesity in the United States27 and the attractiveness
and ease of obtaining weight loss products will probably increase the use
of both prescription and nonprescription products. With this increase comes
a greater need for health care professionals to take an active role in educating
themselves to help their patients make appropriate choices.