Research article| Volume 26, ISSUE 5, P402-406, June 01, 2004

# Attempting to lose weight

## Abstract

Americans spend over $33 billion annually on weight-loss products and services. Although weight-control methods are of considerable public health interest, few national data on weight-loss practices are available. This paper examines the prevalence of specific weight-loss practices among U.S. adults trying to lose weight. ### Methods Data from the 1998 National Health Interview Survey, which was conducted through face-to-face interviews of a nationally representative sample of U.S. adults (n =32,440), were analyzed in 2003. ### Results Twenty-four percent of men and 38% of women were trying to lose weight. Attempting weight loss was less common among normal weight (body mass index [BMI]<25 kg/m2) people (6% men, 24% women) than overweight (BMI≥25 to 30 kg/m2) people (28%, 49%) or obese (BMI≥30 kg/m2) people (50%, 58%). Among those trying to lose weight, the most common strategies were eating fewer calories (58% men, 63% women); eating less fat (49%, 56%); and exercising more (54%, 52%). Less frequent strategies were skipping meals (11% men, 9% women); eating food supplements (5%, 6%); joining a weight-loss program (3%, 5%); taking diet pills (2%, 3%); taking water pills or diuretics (1%, 2%); or fasting for ≥24 hours (0.6%, 0.7%). Only one third of all those trying to lose weight reported eating fewer calories and exercising more. ### Conclusions Increased efforts are needed among all those trying to lose weight to promote effective strategies for weight loss, including the use of calorie reduction and increased physical activity. ## Introduction The current national preoccupation with weight loss and dieting is demonstrated by the fact that Americans now spend over$33 billion annually on related products and services.

Cleland R, Graybill D, Hubbard V, et al. Commercial weight loss products and programs: what consumers stand to gain and lose. Washington DC: Federal Trade Commission, Bureau of Consumer Protection, 1998

Despite these expenditures, Americans are getting heavier—nearly 30.5% are obese.
• Flegal K.M
• Carroll M.D
• Ogden C.L
• Johnson C.L
Prevalence and trends in obesity among US adults, 1999–2000.
Obesity is a known risk factor for numerous chronic diseases,

U.S. Department of Health and Human Services. The Surgeon General's call to action to prevent and decrease overweight and obesity 2001. Rockville MD: U.S. Department of Health and Human Services, Public Health Service, Office of the Surgeon General, 2001

and clinical trials have shown that even modest weight loss can reduce risk factors for such diseases.

National Institutes of Health, National Heart, Lung and Blood Institute. Clinical guidelines on the identification, evaluation and treatment of overweight and obesity in adults: the evidence report. Rockville MD: U.S. Department of Health and Human Services, Public Health Service, 1998

Current guidelines recommend that all individuals trying to lose weight use both reduced caloric intake and increased physical activity.

National Institutes of Health, National Heart, Lung and Blood Institute. Clinical guidelines on the identification, evaluation and treatment of overweight and obesity in adults: the evidence report. Rockville MD: U.S. Department of Health and Human Services, Public Health Service, 1998

Even with the recent increase in obesity,
• Flegal K.M
• Carroll M.D
• Ogden C.L
• Johnson C.L
Prevalence and trends in obesity among US adults, 1999–2000.
few national studies on specific weight-loss strategies have been published since the early 1990s.
• Horm J
• Anderson K
Who in America is trying to lose weight?.
,
• Serdula M.K
• Williamson D.F
• Galuska D.A
• Mendlein J.M
• Heath G.W
Prevalence of attempting weight loss and strategies for controlling weight.
,
• Kettel Khan L
• Serdula M.K
• Bowman B.A
• Williamson D.F
Use of prescription weight loss pills among US adults in 1996–1998.
A better understanding of current weight-control strategies among Americans may help the promotion of more effective weight-management practices.
Data from the 1998 National Health Interview Survey were used to describe the prevalence of weight-loss strategies among U.S. adults and are analyzed in 2003. The objectives of this article were to describe characteristics of people trying to lose weight and, among those who reported doing so, to describe specific weight-loss strategies and characteristics of those who used the recommended weight-loss strategies of calorie reduction and increased physical activity.

## Methods

The National Health Interview Survey is an annual survey of non-institutionalized civilian adults in the United States. It is operated by the National Center for Health Statistics, and data are collected by the U.S. Bureau of the Census through face-to-face interviews. The National Health Interview Survey uses a stratified, multistage probability design to sample a U.S. non-institutionalized household population. The overall response rate for sampled adults was 73.9%.

U.S. Department of Health and Human Services. 1998 National Health Interview Survey (NHIS): public use data release. Hyattsville MD: U.S. Department of Health and Human Services, 2000

Analyses were conducted using the adult (≥18 years) sample (n =32,440).
Respondents were asked, “Are you now trying to lose weight, gain weight, stay about the same, or are you not trying to do anything about your weight?” Respondents who answered that they were trying to lose weight were then asked, “Are you currently doing any of these things to control your weight?” and were shown a flash card with 12 specific weight-control strategies: nothing, joined a weight-loss program, eating fewer calories, eating special food products such as canned or powdered food supplements, exercising more, eating less fat, skipping meals, taking diet pills, taking laxatives, taking water pills or diuretics, vomiting, and fasting for ≥24 hours. Respondents were asked to select as many strategies as appropriate. The response items were not mutually exclusive and any possible combination of these strategies could describe respondents' weight-loss practices.
Two analyses were performed, the first of which was used to characterize those trying to lose weight. Among all respondents, those with missing data on demographic characteristics (n =476), on weight and height (n =1154), and on whether they were currently trying to control their weight (n =351) were excluded. Among those trying to lose weight, people with missing information on specific weight-control strategies (n =26) were excluded. The final sample consisted of 30,433 men and women. The second analysis described specific weight-control strategies among adults trying to lose weight. Thus, of the 30,433 respondents, those not trying to lose weight (n =21,014) were excluded. The final sample for the second analysis was 9419.
Data on self-reported height and weight were used to calculate body mass index (BMI) as weight (kg) divided by height (m2). Respondents were assigned to one of three categories—normal weight (BMI<25) overweight (BMI≥25 to <30) and obese (BMI≥30).

National Institutes of Health, National Heart, Lung and Blood Institute. Clinical guidelines on the identification, evaluation and treatment of overweight and obesity in adults: the evidence report. Rockville MD: U.S. Department of Health and Human Services, Public Health Service, 1998

Among adults trying to lose weight, those meeting the recommended weight-loss strategy were defined as people who used the combination of eating fewer calories and exercising more.

National Institutes of Health, National Heart, Lung and Blood Institute. Clinical guidelines on the identification, evaluation and treatment of overweight and obesity in adults: the evidence report. Rockville MD: U.S. Department of Health and Human Services, Public Health Service, 1998

The SUDAAN (Windows version 8.0; Research Triangle Institute, Research Triangle Park NC, 2001) software program was used to accommodate the complex sampling design. Gender-specific prevalence of those trying to lose weight was calculated by the following sociodemographic characteristics: age, race/ethnicity, education, marital status, and BMI. Among those attempting to lose weight, the overall and gender-specific prevalence of the 12 specific weight-loss practices were calculated. Multiple variable logistic regression was used to examine the association between sociodemographic factors and the use of the recommended strategy of eating fewer calories and exercising more.

## Results

The prevalence of those trying to lose weight was 24.3% for men and 37.6% for women (Table 1). In all sociodemographic categories, more women than men were attempting weight loss. Among both genders, the lowest prevalence was among people aged ≥65 years as compared to younger counterparts. The proportion of people trying to lose weight increased with increasing level of education. The prevalence also rose with BMI; among men the prevalence of those trying to lose weight climbed from 6% to 28% to 50%, for people in the normal, overweight, and obese categories, respectively, whereas for women comparable estimates were 24%, 49%, and 58%, respectively.
Table 1Prevalence of attempting to lose weight among U.S. adults (≥18 years), by gender
Source of data is National Health Interview Survey, 1998.
CharacteristicMen (n=13,548)Women (n=16,885)
n
Unweighted sample size of those who self-reported that they wanted to lose weight.
%
Percentage is weighted to be nationally representative.
n
Unweighted sample size of those who self-reported that they wanted to lose weight.
%
Percentage is weighted to be nationally representative.
Age (years)
18–2955219.8122638.5
30–44113825.6218641.4
45–64113929.5195341.9
≥6542118.280423.1
Race/ethnicity
Non-Hispanic white232824.8412537.9
Non-Hispanic black34522.291939.1
Hispanic49124.996736.3
Non-Hispanic other
Includes American Indians and Alaska natives, Asians, and native Hawaiians and other Pacific islanders.
8618.415828.7
Education
Less than high school46916.8103528.8
High school78520.3180536.5
Some college99126.7200042.5
Marital status
Married190326.3310739.9
Widowed9515.258622.8
Divorced38425.589240.1
Separated7519.024238.1
Single79320.5134237.5
Body mass index (kg/m2)
Normal (<25)2905.7190024.0
Overweight (25 to <30)160728.0222249.0
Obese (≥30)135350.1204758.3
Total325024.3616937.6
a Source of data is National Health Interview Survey, 1998.
b Unweighted sample size of those who self-reported that they wanted to lose weight.
c Percentage is weighted to be nationally representative.
d Includes American Indians and Alaska natives, Asians, and native Hawaiians and other Pacific islanders.
Among people trying to lose weight, the top three specific strategies for men and women were eating fewer calories, eating less fat, and exercising more (Table 2). Other strategies that were less common in both men and women included skipping meals, doing nothing, eating food supplements, joining a weight-loss program, taking diet pills, taking water pills or diuretics, fasting for ≥24 hours, taking laxatives, and vomiting. The proportion of men and women who engaged in specific weight-loss practices differed significantly for several practices, but the magnitude of the difference was small. Women were significantly (p <0.05) more likely than men to engage in several strategies, including eating fewer calories, eating less fat, joining a weight-loss program, and taking diet pills. Men were more likely than women to skip meals or do nothing.
Table 2Specific weight-loss practices among adults (≥18 years) trying to lose weight, by gender
Source of data is National Health Interview Survey, 1998.
CharacteristicTotal (n=9419) %
Percentage is weighted to be nationally representative.
Men (n=3250)Women (n=6169)
n
Unweighted sample size of those who self-reported that they were engaging in specific weight-loss practices.
%
Percentage is weighted to be nationally representative.
n
Unweighted sample size of those who self-reported that they were engaging in specific weight-loss practices.
%
Percentage is weighted to be nationally representative.
Eating fewer calories61.0187657.6382663.0
Significant difference between men and women p<0.01.
Eating less fat53.2160749.1336855.7
Significant difference between men and women p<0.01.
Exercising more53.0172754.0318252.3
Skipping meals9.835910.95969.1
Significant difference between men and women, p<0.05.
Nothing8.73209.75118.0
Significant difference between men and women, p<0.05.
Eating food supplements5.81695.33776.0
Joined a weight-loss program4.5922.93215.4
Significant difference between men and women p<0.01.
Taking diet pills2.5501.71873.0
Significant difference between men and women p<0.01.
Taking water pills or diuretics1.7521.41261.9
Fasting for ≥24 hours
Estimates may be unstable.
0.7190.6460.7
Taking laxatives
Estimates may be unstable.
0.4100.3300.4
Vomiting
Estimates may be unstable.
0.140.170.1
* Significant difference between men and women, p<0.05.
∗∗ Significant difference between men and women p<0.01.
a Source of data is National Health Interview Survey, 1998.
b Percentage is weighted to be nationally representative.
c Unweighted sample size of those who self-reported that they were engaging in specific weight-loss practices.
d Estimates may be unstable.
Thirty-four percent of subjects trying to lose weight reported using the recommended strategy of eating fewer calories and exercising more, and women had greater odds of using this strategy (adjusted odds ratio [OR]=1.30; 95% confidence interval [CI]=1.17–1.46) than men (Table 3). Persons of Hispanic origin had significantly lower odds (OR=0.80; 95% CI=0.68–0.92) of eating fewer calories and exercising more than did non-Hispanic whites. Persons who used the recommended weight-loss strategy had higher levels of education. As compared to normal-weight people, people who were overweight but not obese had slightly greater odds of using the recommended strategy to lose weight (OR=1.15; 95% CI=1.01–1.32). There was little association between using the recommended strategy and age or marital status.
Table 3The associations between those using recommended weight-loss strategies
The recommended weight-loss strategy includes eating fewer calories and exercising more.
and characteristics among adults trying to lose weight
Source of data is National Health Interview Survey, 1998.
Characteristicn
Unweighted sample size of those using the recommended weight-loss strategy.
%
Percentage is weighted to be nationally representative.
OR
OR adjusted for gender, age, race, education, marital status, and body mass index.
95% CI
Gender
Men102832.31.0
Women210935.51.301.17–1.46
Age (years)
18–2957031.61.0
30–44119337.01.191.03–1.37
45–64103235.11.110.95–1.29
≥6534228.50.940.77–1.16
Race/ethnicity
Non-Hispanic white228535.61.0
Non-Hispanic black38731.50.890.77–1.04
Hispanic38527.00.800.68–0.92
Non-Hispanic other
Includes American Indians and Alaska natives, Asians, and native Hawaiians and other Pacific islanders.
8033.80.860.62–1.19
Education
Less than high school32822.41.0
High school73129.31.331.11–1.59
Some college105535.11.751.48–2.07
Marital status
Married173135.41.00
Widowed18527.50.870.69–1.08
Divorced39632.30.870.75–1.01
Separated9228.00.840.62–1.15
Single73333.81.030.89–1.19
Body mass index (kg/m2)
Normal (<25)76535.31.00
Overweight (25 to <30)131135.21.151.01–1.32
Obese (≥30)106132.51.110.97–1.27
Total313734.3%
CI, confidence interval; OR, odds ratio.
a The recommended weight-loss strategy includes eating fewer calories and exercising more.
b Source of data is National Health Interview Survey, 1998.
c Unweighted sample size of those using the recommended weight-loss strategy.
d Percentage is weighted to be nationally representative.
e OR adjusted for gender, age, race, education, marital status, and body mass index.
f Includes American Indians and Alaska natives, Asians, and native Hawaiians and other Pacific islanders.
The three most common weight-loss strategies were examined by BMI and, compared to normal-weight respondents, obese respondents were more likely to eat fewer calories (p<0.01) and less likely to exercise more (p <0.01). There was no difference in eating less fat by weight status (data not shown).

## Discussion

This national survey demonstrates that 31% of U.S. adults were currently trying to lose weight. Within that group, the following findings were documented: (1) the three most common weight-loss strategies were eating fewer calories, eating less fat, and exercising more; (2) one third of those attempting weight loss engaged in the recommended strategy of eating fewer calories and exercising more; and (3) although more women than men were trying to lose weight, both genders followed similar weight-control strategies.
The finding that 24% of men and 38% of women were trying to lose weight in 1998 is similar to the prevalences reported in both the 1985 (23.2% of men; 41.3% of women) and the 1990 (23.3% of men and 40.1% of women) National Health Interview Surveys, which used identical questions.
• Horm J
• Anderson K
Who in America is trying to lose weight?.
The prevalence found in this paper is slightly lower than that in the 1996 Behavioral Risk Factor Surveillance Survey (BRFSS), a multistate telephone survey of U.S. adults, aged ≥18. In the BRFSS, 29% of men and 44% of women reported that they were trying to lose weight.
• Serdula M.K
• Williamson D.F
• Galuska D.A
• Mendlein J.M
• Heath G.W
Prevalence of attempting weight loss and strategies for controlling weight.
In this study, the prevalence of trying to lose weight increased with BMI. It is surprising that the prevalence of trying to lose weight has not increased, given that the prevalence of obesity among U.S. adults has increased 8.0% between 1988–1994 and 1999–2000.
• Flegal K.M
• Carroll M.D
• Ogden C.L
• Johnson C.L
Prevalence and trends in obesity among US adults, 1999–2000.
Unfortunately, it was not possible to directly compare the prevalence of trying to lose weight by weight status between the findings of this study and earlier surveys, as weight and height were not collected in the 1985 and 1990 National Health Interview Survey. Two factors associated with not trying to lose weight are lack of success at previous weight-loss attempts
• Brownell K.D
• Rodin J
The dieting maelstrom.
and satisfaction with body weight.
• Anderson L.A
• Eyler A.A
• Galuska D.A
• Brown D.R
• Brownson R.C
Relationship of satisfaction with body size and trying to lose weight in a national survey of overweight and obese women aged 40 and older, United States.
Their prevalence possibly has changed over time, although we are unaware of studies that specifically examine trends in these factors.
Despite the known benefits of weight loss,

U.S. Department of Health and Human Services. The Surgeon General's call to action to prevent and decrease overweight and obesity 2001. Rockville MD: U.S. Department of Health and Human Services, Public Health Service, Office of the Surgeon General, 2001

only half of obese respondents of both genders were trying to lose weight (50% of men and 58% of women). The National Institutes of Health clinical guidelines recommend that clinicians discuss weight loss with people who are obese.

National Institutes of Health, National Heart, Lung and Blood Institute. Clinical guidelines on the identification, evaluation and treatment of overweight and obesity in adults: the evidence report. Rockville MD: U.S. Department of Health and Human Services, Public Health Service, 1998

Consistent with clinical guidelines, clinicians should continue to counsel the obese to reduce their body weight.
Respondents trying to lose weight used a variety of strategies, and this study evaluated the prevalence of 12 weight-loss strategies in a nationally representative sample. Eating fewer calories, eating less fat, and exercising more were the most common strategies and were used by approximately half of those trying to lose weight. However, only one third of adults trying to lose weight reported using the recommended weight-loss strategy of eating fewer calories and exercising more. The findings in this article are higher than that reported in the 1996 BRFSS, which found that 22% of men and 19% of women reported eating fewer calories and engaging in at least 150 minutes of leisure-time physical activity per week.
• Serdula M.K
• Williamson D.F
• Galuska D.A
• Mendlein J.M
• Heath G.W
Prevalence of attempting weight loss and strategies for controlling weight.
This may be, in part, because the BRFSS more strictly defined using exercise as 150 minutes of leisure-time physical activity per week, whereas our study included anyone who reported exercising more to lose weight.
Other weight-loss practices were reported by <11% of respondents. Consistent with other surveys,
• Serdula M.K
• Williamson D.F
• Anda R.F
• Levy A
• Heaton A
• Byers T
,
• Levy A.S
• Heaton A.W
Weight control practices of US adults trying to lose weight.
the prevalence of unhealthy weight-loss strategies such as fasting, taking laxatives, and vomiting was low. In contrast to these unhealthy practices, use of prescription weight-loss pills may be appropriate for some individuals as an adjunct for weight-loss therapy.

National Institutes of Health, National Heart, Lung and Blood Institute. Clinical guidelines on the identification, evaluation and treatment of overweight and obesity in adults: the evidence report. Rockville MD: U.S. Department of Health and Human Services, Public Health Service, 1998

However, it was not possible to tell from the data whether respondents were using prescription or nonprescription diet pills. In this study, 2% of men and 3% of women reported currently taking diet pills. The 1998 estimates of diet pill consumption are higher than the 1990 National Health Interview Survey finding that showed 0.6% of adults were currently taking diet pills.
• Horm J
• Anderson K
Who in America is trying to lose weight?.
This observation is consistent with the growing popularity of diet supplements for weight loss and prescription diet pills since the 1990s.
Marketdata Enterprises Inc
Diet segment bulks up.
Women were about twice as likely to be attempting to lose weight as men. This might be explained in part by the finding that more women than men were trying to lose weight at a lower BMI (6% of normal-weight men versus 24% of normal-weight women). In contrast, among those who were obese, the gender-specific differential was modest: 50% of men and 58% of women were trying to lose weight. We speculate that this gender-specific difference may be because women have a greater concern for thinness and a higher level of body dissatisfaction than men.
• Cachelin F.M
• Striegel-Moore R.H
• Elder K.A
Realistic weight perception and body size assessment in a racially diverse community sample of dieters.
Despite the differences between men's and women's attempting to lose weight, there were only small gender-specific differences in the prevalence of specific weight-loss strategies among those trying to lose weight.
Our findings should be viewed in the context of several limitations. First, the estimates of weight-loss practices are based on self-report. We are unaware of studies specifically validating individuals' responses with their actual practice. It is possible that socially undesirable behaviors such as vomiting or taking laxatives were under-reported and socially desirable behaviors such as being physically active were over-reported. Second, the questionnaire provided limited detail in terms of the intensity (e.g., amount of caloric reduction or frequency of diet pill use) of weight-loss practices. The strategy of doing nothing was included in this analysis to allow for comparison with previous analyses using the same survey. However, it is not clear if respondents misunderstood the question or whether respondents realistically reported that they were trying to lose weight with minimal effort. Third, because BMI was based on self-reported weight, overweight and obesity may be underestimated.
• Rowland M.L
Self-reported weight and height.
Fourth, this study did not ascertain the effectiveness of the weight-loss strategies reported. Fifth, data on some popular weight-loss diets such as restricted carbohydrate intake were not collected in this survey. Finally, this analysis is based on 1998 data and may not reflect current weight-loss approaches.
Attempting weight loss is a common health behavior in the United States. Although one in every three adults is trying to lose weight, not all people who would benefit from weight loss are making an attempt. Furthermore, many who are trying to lose weight are not using effective strategies. Increased efforts are needed to promote effective weight-loss strategies among those who are obese and to promote the use of calorie reduction along with increased physical activity in those who attempt weight loss.

## Acknowledgements

No financial support was provided for this manuscript.

## References

1. Cleland R, Graybill D, Hubbard V, et al. Commercial weight loss products and programs: what consumers stand to gain and lose. Washington DC: Federal Trade Commission, Bureau of Consumer Protection, 1998

• Flegal K.M
• Carroll M.D
• Ogden C.L
• Johnson C.L
Prevalence and trends in obesity among US adults, 1999–2000.
JAMA. 2002; 288: 1723-1727
2. U.S. Department of Health and Human Services. The Surgeon General's call to action to prevent and decrease overweight and obesity 2001. Rockville MD: U.S. Department of Health and Human Services, Public Health Service, Office of the Surgeon General, 2001

3. National Institutes of Health, National Heart, Lung and Blood Institute. Clinical guidelines on the identification, evaluation and treatment of overweight and obesity in adults: the evidence report. Rockville MD: U.S. Department of Health and Human Services, Public Health Service, 1998

• Horm J
• Anderson K
Who in America is trying to lose weight?.
Ann Intern Med. 1993; 117: 672-676
• Serdula M.K
• Williamson D.F
• Galuska D.A
• Mendlein J.M
• Heath G.W
Prevalence of attempting weight loss and strategies for controlling weight.
JAMA. 1999; 282: 1353-1358
• Kettel Khan L
• Serdula M.K
• Bowman B.A
• Williamson D.F
Use of prescription weight loss pills among US adults in 1996–1998.
Ann Intern Med. 2001; 134: 282-286
4. U.S. Department of Health and Human Services. 1998 National Health Interview Survey (NHIS): public use data release. Hyattsville MD: U.S. Department of Health and Human Services, 2000

• Brownell K.D
• Rodin J
The dieting maelstrom.
Am Psychol. 1994; 49: 781-791
• Anderson L.A
• Eyler A.A
• Galuska D.A
• Brown D.R
• Brownson R.C
Relationship of satisfaction with body size and trying to lose weight in a national survey of overweight and obese women aged 40 and older, United States.
Prev Med. 2002; 35: 390-396
• Serdula M.K
• Williamson D.F
• Anda R.F
• Levy A
• Heaton A
• Byers T
Am J Public Health. 1994; 84: 1821-1824
• Levy A.S
• Heaton A.W
Weight control practices of US adults trying to lose weight.
Ann Intern Med. 1993; 119: 661-666
• Marketdata Enterprises Inc
Diet segment bulks up.
Nutr Business J. 2000; 5: 3-5
• Cachelin F.M
• Striegel-Moore R.H
• Elder K.A
Realistic weight perception and body size assessment in a racially diverse community sample of dieters.
Obes Res. 1998; 6: 62-67
• Rowland M.L
Self-reported weight and height.
Am J Clin Nutr. 1990; 52: 1125-1133