Public Health Recomendations Analysis
Many public health recommendations and clinical guidelines emphasize the importance of healthy lifestyles. Recent epidemiologic studies demonstrate that following a healthy lifestyle has substantial health benefits. The objectives of this study were to report on the prevalence of healthy lifestyle characteristics (HLCs) and to generate a single indicator of a healthy lifestyle.
Methods: National data for the year 2000 were ob- port prevalences of each HLC and the indicator by major demographic subgroups.
Results: By using data from more than 153 000 adults, the prevalence (95% confidence interval) of the individual HLCs was as follows: nonsmoking, 76. 0% (75. 6%76. 4%); healthy weight, 40. 1% (39. 7%-40. 5%); 5 fruits and vegetables per day, 23. 3% (22. 9%-23. 7%); and regular physical activity, 22. 2% (21. 8%-22. 6%). The overall prevalence of the healthy lifestyle indicator (ie, having all 4 HLCs) was only 3. % (95% confidence interval, 2. 8%-3. 2%), with little variation among subgroups (range, 0. 8%-5. 7%).
Conclusion: These data illustrate that a healthy lifestyle— trained from the Behavioral Risk Factor Surveillance System, which consists of annual, statewide, random digit– dialed household telephone surveys. We defined the following 4.
HLCs: nonsmoking, healthy weight (body mass index [calculated as weight in kilograms divided by the square of height in meters] of 18. 5-25. ), consuming 5 or more fruits and vegetables per day, and regular physical activity ( 30 minutes for 5 times per week).
The 4 HLCs were summed to create a healthy lifestyle index (range, 0-4), and the pattern of following all 4 HLCs was defined as a single healthy lifestyle indicator. We redefined as a combination of 4 HLCs—was undertaken by very few adults in the United States, and that no subgroup followed this combination to a level remotely consistent with clinical or public health recommendations. However, only 3% of the nurses actually engaged in this lifestyle. We chose to estimate the prevalence of 4 healthy lifestyle characteristics (HLCs) (ie, nonsmoking, healthy weight, fruit, and vegetable consumption, and leisure-time physical activity [LTPA]) using a nationally representative sample of US adults, and to generate a single indicator of a healthy lifestyle defined by undertaking all 4 HLCs.
METHODS
The Behavioral Risk Factor Surveillance System (BRFSS) is composed of annual, statewide, random digit–dialed household telephone surveys of adults. 17,18 We pooled the 2000 BRFSS responses from all 50 states and the District of Columbia and restricted the sample to respondents aged 18 to 74 years. The median Author Affiliations: Department of Epidemiology, College of Human Medicine, Michigan State University, East Lansing (Dr. Reeves); and Bureau of Epidemiology, Michigan Department of Community Health, Lansing (Dr. Rafferty).
Financial Disclosure: None. N THE UNITED STATES AND worldwide, chronic diseases account for the greatest overall population disease burden in terms of mortality, morbidity, and decreased quality of life.
- Most people with major chronic diseases share multiple common lifestyle characteristics or behaviors, particularly smoking, poor diet, physical inactivity, and obesity.
- Tobacco, poor diet, and physical inactivity have been identified as leading contributors to overall mortality in the United States. The public health importance of these lifestyle characteristics can also be gauged by their inclusion in major public health reports on smoking,4,5 physical activity,6 and diet,7 and in clinical guidelines concerning blood pressure, 8 cholesterol, 9 and obesity, 10 which all emphasize lifestyle modification as a key element of prevention and control.
Obtains 30 minutes or more of LTPA at least 5 times per week. cooperation rate of the state-specific surveys was 51. 3% (range, 33. 4%-75. 5%). All data were based on self-report. Healthy weight was defined as a body mass index (calculated as weight in kilograms divided by the square of height in meters) between 18. 5 and 25. 0. 10 Food frequency questions were used to measure the consumption of fruit juice, fruit, green salad, potatoes (excluding fried products), carrots, and other vegetables, and adequate consumption was defined as eating fruits and vegetables 5 or more times per day. Leisure-time physical activity was based on questions regarding the frequency and duration of up to 2 activities. Regular LTPA was defined as 30 minutes or more of at least moderate-intensity physical activity 5 or more times per week. 6 We created an index of a healthy lifestyle by summing the total number of HLCs for each respondent (range, 0-4), and then defined the pattern of following all 4 HLCs as a single indicator of a healthy lifestyle (ie, index of healthy lifestyle = 4). There are 16 possible unique permutations or combinations of the 4 HLCs; however, only 2 were followed by more than 10% of the population (nonsmokers with no other HLCs made up 29. 0%, and nonsmokers with a healthy weight represented 16. 1%). The 9. 4% of subjects who did not engage in any of the 4 HLCs were the next most common group.
(REPRINTED) ARCH INTERN MED/ VOL 165, APR 25, 2005 856 The results generated from this nationally representative database indicate that just 3. % of US adults followed a combination of 4 modifiable lifestyle characteristics—nonsmoking, healthy weight, adequate fruit and vegetable consumption, and regular physical activity. No subgroup engaged in all 4 healthy lifestyles to any important degree— the highest prevalence being only 5. 7%. These results illustrate the extraordinarily low prevalence of healthy lifestyles in the US adult population.
While the overall prevalence of 3. 0% was extremely low, it is identical to that reported in the Nurses’ Health Study15,16 and similar to reports generated from the Third National Health and Nutrition Examination Survey. 1,22 The low prevalence of the healthy lifestyle indicator in our study is a function of the prevalence of the individual HLCs and how they aggregate or cluster together. While three-quarters of US adults do not smoke, the prevalences of the other 3 lifestyles were quite low. Only two-fifths of the population had a healthy weight, while only a quarter consumed adequate fruits and vegetables or engaged in regular LTPA. How these factors then combine together is dependent on the degree to which they are correlated.
While it is commonly recognized that smoking and alcohol are associated with one another,23 the degree of association between other lifestyle characteristics is less clear. 22,24-27 If the 4 HLCs were statistically independent, the expected prevalence of the indicator would be 1. 5%, which indicates that the actual magnitude of association among these HLCs is small to nonexistent. This finding is in agreement with those of other studies that have found that while health behaviors are interrelated, the magnitude of the relationship is not large and the aggregation of factors beyond simple pairwise correlations is complex. 2,24-27 There are several potential limitations to our study. First, these data are open to the limitations inherent in self-reported data. 28 Second, the BRFSS captures information on LTPA only, which may underestimate total activity, and BRFSS estimates of daily fruit and vegetable consumption are lower than those based on more extensive food frequency questionnaires. 29 Noncoverage and nonresponse biases typical of telephone surveys may affect our estimates. Specifically, comparisons made to the US census indicate that BRFSS respondents are slightly more likely to be older, female, white, and more educated.
It is for this reason that some health behavior studies have not included body mass index22; however, we chose to include it because of its public health importance. Other studies15,16,22 have included moderate alcohol consumption as a healthy lifestyle factor because of its overall benefits in reducing cardiovascular risk. However, we chose not to include alcohol consumption in our index because of the difficulty in developing a clear, unified, public health recommendation on this topic. Finally, it could be argued that combining all 4 HLCs into a single indicator is too extreme because the prevalence of the indicator is unlikely to change in response to public health interventions. However, we believe that our approach offers a single figure that can serve as a useful population-level indicator of healthy lifestyle behaviors for surveillance purposes, and a measure that could be useful when counseling individual patients about healthier lifestyles. In summary, we found that only 3. 0% of US adults followed 4 common modifiable HLCs.
