Most women in the United States do not meet minimum recommendations for physical activity or fruit/vegetable consumption. Thus, many are overweight/obese and are at increased risk for cancer morbidity and mortality. This study investigated women’s perceptions about the importance of physical activity and a healthy diet in preventing cancer, perceptions of engaging in these behaviors, and whether or not the behaviors met cancer prevention recommendations.
A cross-sectional, national, random-digit-dialed telephone survey was conducted with 800 women, ages 18 and older. The response rate was 24.5%. Measures assessed demographics, perceived health status, beliefs about the role of physical activity and diet in cancer prevention, perceived engagement in these behaviors, and actual behaviors.
Only 9.9% of women who reported eating a healthy diet met minimum fruit and vegetable recommendations; 39.7% of women who reported regular physical activity met the minimum recommendation. Analyses adjusted for demographics indicated that low education was associated with reporting regular physical activity to prevent cancer, yet failing to meet the minimum recommendation (odds ratio [OR]=0.90, 95% confidence interval [CI]: 0.82–0.98, p=0.01). Racial/ethnic minority status was marginally significantly associated with reporting eating a healthy diet to prevent cancer, yet failing to consume sufficient fruits and vegetables (OR=2.94, 95% CI: 0.99–8.71, p=0.05).
Most women who reported eating a healthy diet and being physically active to prevent cancer failed to meet the minimum cancer prevention recommendations. Furthermore, low socioeconomic status and racial/ethnic minority women may be particularly vulnerable to discrepancies between beliefs and behavior.
Among women in the united states, the lifetime risk of cancer is slightly more than one in three.1 It was estimated that in 2010, 739,940 new cases of cancer would be diagnosed among women and that 270,290 women would die from cancer.1 Approximately one-third of these deaths were expected to be directly attributable to poor nutrition, physical inactivity, and overweight/obesity.1 Recent data indicate that 64.1% of U.S. women are overweight or obese.2 The American Cancer Society recommends that U.S. adults get at least 30 minutes of moderate physical activity 5 days per week and eat at least two servings of fruit and three servings of vegetables per day.3 Nevertheless, 52.5% of women fail to meet the minimum recommendations for physical activity; 64.9% fail to consume the minimum recommended daily servings of fruits, and 69.1% do not consume the minimum recommended daily servings of vegetables.4,5 It is notable that numerous studies support the difficulty of maintaining even relatively short-term changes in physical activity.6,7 As most American women do not meet the minimum cancer prevention guidelines, many opportunities for cancer prevention might be missed. There is a critical need for research intended to improve the adoption and maintenance of cancer prevention behaviors related to diet and physical activity among women in the United States.
In general, research has supported positive associations among knowledge, beliefs, and behaviors relevant to cancer prevention. Knowledge of the American Cancer Society’s dietary recommendations and the belief that diet influences the risk of developing cancer have been found to prospectively predict the adoption of healthy dietary changes.8 Other data have indicated that individuals with poor dietary behaviors who are likely to benefit from diet-related changes may not perceive a need to make such changes.9 These findings may reflect limited knowledge regarding the importance of change, or past failures among individuals attempting to initiate and maintain healthy dietary changes.7 Considerable data indicate that individuals with the lowest levels of education, income, and working or occupational status—those with low socioeconomic status (SES)—practice poorer health behaviors, have poorer health outcomes, live in poorer neighborhoods, and have more limited resources for the prevention, early detection, and treatment of cancer.10,11 Additionally, there are important racial/ethnic and socioeconomic disparities in the prevalence of overweight/obesity that contribute to cancer disparities among women. In the United States, rates of overweight and obesity are significantly higher among African American and Latina women compared with non-Latina white women,12 and significantly higher among women with lower (vs. higher) SES.13Elucidating how perceptions of behavior may be related to actual diet and physical activity behavior among racial/ethnic minority women and women of low SES is an important research agenda.
Although previous findings suggest a positive relationship between knowledge, beliefs, and behaviors related to cancer prevention, no prior studies that we know of have investigated how beliefs about certain health behaviors (e.g., physical activity, healthy eating) might prevent cancer and predict the regular practice of recommended cancer prevention behaviors. Further, no studies have assessed whether those who report engaging in cancer prevention behaviors do so with sufficient frequency and duration to meet current cancer prevention guidelines. We are also unaware of research examining predictors of potential discrepancies between beliefs about engaging in behaviors to help prevent cancer and compliance with minimum recommendations. The present study sought to address these gaps in the literature.
The primary goal of this study was to investigate women’s perceptions of the importance of diet (i.e., fruit and vegetable consumption) and physical activity in helping to prevent cancer, their perceptions regarding the frequency with which they engaged in these behaviors to help prevent cancer, and whether or not the frequencies with which they engaged in these behaviors were sufficient to meet the minimum recommendations for cancer prevention established by the American Cancer Society.3 Socio-demographic and racial/ethnic predictors of potential discrepancies between perceived behavior and compliance with minimum recommendations for cancer prevention were also assessed.
Materials and Methods
The data were collected via a cross-sectional, national, random-digit-dialed (RDD) telephone survey of 800 women. The survey assessed general health and lifestyle issues and was created for this study (measures and questions of interest are described below).
Inclusion criteria required that respondents be female, at least 18 years of age, and speak English. All participants were members of a convenience survey pool; however, we attempted to obtain a racially/ethnically diverse sample roughly equivalent to demographics reported in the 2000 U.S. Census (e.g., 69.1% non-Latino white; 12.5% Latino, 12.1% African American).14 Study staff attempted to contact each participant only once. A total of 3,261 surveys were attempted, and 800 interviews were completed, resulting in a response rate of 24.5%. Survey administration took approximately 20 minutes. All data were collected in May 2007 by Gelb Consulting.
Demographics assessed included gender, age, race/ethnicity, educational attainment, marital status, employment, annual household income, and insurance status.
Perceived general health was assessed using a single item from the 2006 Behavioral Risk Factor Surveillance (BRFSS) survey15 that read, “Would you say that in general your health is _____?” Response options included excellent, very good, good, fair, poor, and don’t know.
Beliefs about cancer prevention behaviors were assessed by asking participants if they believed that eating a healthy diet could help prevent cancer from developing, and if they believed that engaging in regular physical activity could help prevent cancer from developing. Response options for both questions were yes, no, and don’t know. These questions were created for the purposes of the present study and were therefore not previously validated.
Perceptions about the practice of behaviors intended to prevent cancer were assessed by asking participants if they regularly consumed a healthy diet, and if they engaged in regular physical activity to help prevent cancer. Response options for both questions were yes, no, and don’t know. Both questions were generated for this study and were not formerly validated.
Fruit and vegetable intake was assessed using two items from the 2006 BRFSS survey.15 The following instructions were read to respondents prior to administration of the two items: “I’d like to ask about the foods you usually eat or drink. Please tell me how often you eat or drink each one, for example, twice a week, three times a month, and so forth. Remember, I am only interested in the foods you eat. Include all foods you eat, both at home and away from home.” The items were: (1) “Not counting juice, how often do you eat fruit?” and (2) “How often do you eat vegetables?” Response options for each item were identical (i.e., __ per day, __ per week, __ per month, __ per year, never, and don’t know/not sure).
Physical activity was assessed using three items from the 2006 BRFSS survey:15 (1) “During the past 30 days, other than your regular job, did you participate in any physical activities or exercises such as running, calisthenics, golf, gardening, or walking for exercise?” The response options were yes, no, and don’t know. (2) “During the past 30 days, how often have you engaged in these physical activities or exercises? Please tell me how many times a day, days a week or days during the month.” (3) “During the past 30 days, about how long at a time did you spend each time you did these physical activities or exercises? Please tell me how many minutes or hours you usually spent.”
Frequencies were examined to determine the percentage of women surveyed who (1) believed that eating a healthy diet and engaging in regular physical activity could help prevent cancer, (2) reported actually eating a healthy diet and engaging in regular physical activity to prevent cancer, and (3) reported behaviors compliant with current minimum cancer prevention guidelines regarding fruit and vegetable consumption and physical activity (i.e., eating at least two servings of fruits and three servings of vegetables daily and getting at least 150 minutes of moderate to vigorous physical activity weekly). Potential demographic differences based on fruit and vegetable consumption and self-reported physical activity were assessed using Chi-square analyses and t-tests for categorical and continuous variables, respectively. Next, Chi-square analyses and t-tests were performed to evaluate potential discrepancies between perceptions of regularly eating a healthy diet and engaging in physical activity to help prevent cancer and meeting the current minimum levels of those behaviors recommended by the American Cancer Society for cancer prevention.
Univariate logistic regression analyses were performed to examine predictors of discrepancies between (1) perceptions of eating a healthy diet to prevent cancer and meeting the minimum recommendation for fruit and vegetable consumption, and (2) perceptions of engaging in regular physical activity to prevent cancer and meeting the minimum recommendation for physical activity. Discrepancies were defined as significant differences, assessed via Chi-square tests, between self-reported consumption of a healthy diet and regular physical activity to help prevent cancer, and actually meeting the minimum recommendations for fruit and vegetable consumption and physical activity. In the logistic regression analyses, the presence of a discrepancy for each participant was coded as 1, and the absence of a discrepancy for each participant was coded as 0. Predictors examined included demographic variables (i.e., age, race/ethnicity, years of education, household income, marital status), and perceived general health. Finally, predictors that were significant in the univariate models were evaluated in multivariate logistic regression models. All multivariate analyses controlled for or included age, race/ethnicity, education, income, and marital status. Race/ethnicity was dichotomized as white versus non-white, and marital status was dichotomized into married/living with partner versus not married/living with partner. All other demographic variables were continuous. Analyses were conducted using IBM SPSS version 19.