J Cancer Prev 2022; 27(2): 79-88
Published online June 30, 2022
© Korean Society of Cancer Prevention
Department of Health Science, College of Graduate Health Studies, A.T. Still University, Mesa, AZ, USA
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
The incidence of colorectal cancer has considerably increased worldwide, particularly among adults aged 50 and older. Despite numerous nutrition initiatives, colorectal cancer (CRC) remains a public health burden that affects younger adults in the United States. Understanding the potential factors contributing to non-adherence to nutrition recommendations can be helpful to develop effective nutrition initiatives to prevent CRC. This study aimed to determine differences in nutrition knowledge, attitudes, and beliefs (KAB); examine their associations on diet characteristics and weight status; and identify factors influencing eating patterns among ethnically diverse populations at risk for CRC and living in urban areas. The study used a quantitative descriptive and correlational research design in which data were collected through an online cross-sectional survey. A total of 377 participants responded to the survey. The study revealed a few significant differences in KAB levels between males and females. KAB levels were not associated with weight status but with meat recommendations among overweight or obese males. Ultimately, the study identified perceived barriers and facilitators as factors influencing participants’ diets. Differences in KAB among males and females were inconsistent with the diet characteristics and weight status variables. This study suggests acknowledging these differences and inconsistencies when designing nutrition initiatives focusing on colorectal cancer prevention.
Keywords: Diet, food, and nutrition, Colorectal neoplasm, Diet, Culture and replace diet with knowledge, Attitudes
Globally, colorectal cancer (CRC) is the second most diagnosed cancer in women and the third most diagnosed cancer in men. Despite numerous health initiatives to reduce CRC incidence, it remains a public health burden. In the United States, although the incidence of CRC has been gradually decreasing among adults aged 50 years and older, it rapidly increases among young adults . Though evidence has revealed poor diets represent 30% to 35% of tumor contributors , and poor lifestyle habits appear to be substantial risk factors for CRC , nutrition has often been ignored as a contributing factor .
Studies focusing on colorectal cancer prevention have identified dietary factors as mediators of CRC. Such factors include diets rich in red, processed, and grilled meats, and alcohol consumption . Castelló et al.  explained approximately 50% of CRC cases could be prevented through lifestyle modifications, including following a healthful diet and maintaining a healthy body weight. To encourage healthier lifestyles and reduce the risk of CRC, some organizations have implemented preventive approaches. For example, the World Cancer Research Fund (WCRF) and the American Institute for Cancer Research (AICR) established recommendations to reduce CRC risk through diets and lifestyle modifications . However, promoting healthy eating involves more than a change in diet. Factors preventing the adoption of healthy eating behaviors may influence individuals’ diet characteristics. Such factors, including facilitators and barriers to healthy eating, were addressed in several studies [8,9].
Other factors, including nutrition knowledge, behavior, and beliefs, were identified in CRC studies through the health behavior model (HBM) and the theory of planned behavior model (TPB) [10,11]. The HBM focuses on individuals’ beliefs regarding health. The main goal of the HBM is to identify and predict health behavior . The model was developed to support research intended to understand why individuals often neglect preventive measures improving health . The TPB posits most factors of behavior correspond to the intention of performing a behavior. Intention is defined as the effort employ to perform a behavior. Intentions are determined by attitudes, evaluation of the benefits or cost to perform the behavior, evaluation of the opinions of significant others regarding the behavior, and the analysis of perceived behavioral control . The TPB is effective in studies addressing nutrition and healthy diets, as it can predict the behavior of individuals and their intentions.
Nutrition approaches to CRC prevention encompass prudent diets and weight status, yet they often omit individuals’ perceived beliefs and behavior. Because poor nutrition remains a substantial factor enhancing the risk of CRC [6,12,14], individuals’ perspectives regarding dietary behavioral changes should be considered during the development of effective interventions. When designing nutrition interventions focused on CRC prevention, assessments of unmet needs should be performed to identify the potential barriers, motivators, and facilitators that influence diets. A few studies focusing principally on CRC survivors have examined health behaviors toward nutrition and CRC [8,15]. Other studies have analyzed the perceptions of cancer patients regarding nutrition and the barriers and motivators influencing cancer patients’ diets [16,17].
Populations at risk of developing CRC are often unaware of the function of nutrition as a tool to ameliorate their lifestyle. Understanding populations’ perceived beliefs regarding diet and evaluating subjects’ knowledge about the benefits of nutrition as a means of CRC prevention can enlighten health professionals to design effective health initiatives. Additionally, identifying whether sex differences exist in regard to dietary choices may help nutritionists and dietitians develop targeted interventions fostering changes in nutritional behavior. Although the previous studies that compared healthy males and females revealed differences in nutritional needs; they mainly focused on dietary characteristics. Therefore, studies identifying factors that may influence dietary choices in men and women at risk of CRC may be an asset in reducing CRC prevalence. The purpose of this quantitative descriptive correlational study is to determine differences in nutrition knowledge, attitudes and beliefs; examine their association on diet characteristics and weight status; and identify factors influencing eating patterns among ethnically diverse populations at risk for CRC and living in urban areas.
A quantitative descriptive and correlational research design was applied to perform the study, and an online cross-sectional survey method was used to collect data. The survey consisted of a food frequency questionnaire (FFQ) of 12 questions evaluating diet characteristics for red meat and processed chicken, fish, sugar-sweetened drinks, alcohol, fibers, and high-calorie foods. The FFQ was created from the recommendations of the WCRF and AICR (limit consumption of red and processed meat; sugar-sweetened drinks; fast foods and other processed food high in fat, starches, or sugar; limit alcohol consumption; eat a diet rich in whole grains, vegetables, fruit, and beans) as well as the recommendation for fish consumption of the World Health Organization (WHO). The FFQ asked participants to recall how often they eat specific foods per month or per week following these options: never, once a month, 2-3 times per month, once a week, 2-3 times per week, 4-6 times per week, and daily consumption. Additionally, the survey included questions addressing nutrition knowledge created from the recommendations of the WCRF and AICR. The use of an FFQ to assess nutrition for colorectal cancer prevention and the WCRF and AICR recommendations were validated and tested in previous studies in that the reproducibility and validity of the FFQ were assessed by comparing FFQ1 against FFQ2, and FFQ1 against a 3-day diary method, respectively. The validity test revealed a reproducibility of more than 85% of the CRC-related food groups and a significant difference for eight CRC- related food groups. The authors suggested the FFQ could be satisfactory for estimating food and nutrient intakes and ranking subjects according to high and low intake categories [7,18].
Ultimately, the survey consisted of questions focusing on beliefs, attitudes, and perceptions regarding nutrition. The questions were adapted from the open-ended questionnaire created by Hardcastle and from the dietary habits and colon cancer beliefs survey created by Smith to create a health belief model and theory of health behavior-based structured questionnaire [10,15]. The questionnaire consisted of 17 questions scored on a 5-point Likert scale and based on four constructs of the HBM (perceived severity, susceptibility, barriers, and cues to action) and two constructs of the TBP (attitudes and behavioral intentions). Perceived severity and susceptibility were categorized as motivators (potential factors that induce motivation to adopt a new behavior) and cues to action represented facilitators (potential factors that facilitate or trigger a behavior change). The HBM and TPB have been tested in previous studies [10,19]. and the questionnaires developed by Hardcastle and Smith were both peer-reviewed for validity.
Participants were recruited online through convenience sampling. Digital flyers were disseminated on online platforms and were provided to organizations fostering cancer prevention. The inclusion criteria included English-speaking adults living in the United States between 30 and 75 years of age. Participants who had a current or past cancer diagnosis of any type were excluded. A total of 547 participants responded to the survey resulting in a response rate of 69%. Seventy respondents were disqualified because they had a history of cancer, they were under 30 years old, or they did not live in the United States, and 100 responses had to be excluded because the participants only partially completed the survey. The final sample consisted of 377 respondents, of whom 289 were females, and 88 were males. The A.T. Still University Institutional Review Board (IRB) committee approved the study (no. IRB #2019-175).
Statistical analyses were conducted for all variables using IBM SPSS Statistics 26.0 (IBM Co., Armonk, NY, USA). Descriptive statistics were used to describe participants’ demographic characteristics, including age, ethnicity, highest level of education, household income, and weight status. Participants’ weight status was represented by the body mass index (BMI), which was categorized into underweight, normal weight, overweight, and obese using the cut-off points of the Centers for Disease Control and Prevention . All demographic data were represented in frequency and percentage. Scales and scores were calculated for the variables of diet characteristics, diet recommendations, knowledge, attitudes, and beliefs.
For each food category of the FFQ, a score of 1 was attributed if the recommendations were met, and a score of 0 was given if the recommendations were not met. Cut-offs for each food group, as established in the study of Hastert and White , were used to calculate the scores. Cut-offs for fish followed the WHO suggestions .
Scores obtained from each diet recommendation were added to obtain a total diet recommendation score that was used as a continuous variable for inferential statistics. Additionally, factors including perceived barriers, facilitators, and motivators comprised a 5-point Likert-scale questionnaire ranging from strongly disagree, disagree, neutral, agree, to strongly agree, and scored as 1, 2, 3, 4, and 5, respectively. Scores for each perceived factor were added to obtain total scores that were used as continuous variables for inferential statistics.
The KAB score represented the sum of the total score obtained from knowledge, attitude, and belief questions. The knowledge section was comprised of five dichotomous questions, with a score of 1 provided for the correct answer and a score of 0 for incorrect and “I don’t know” answers. The attitude and belief sections were comprised of a 5-point Likert-scale questionnaire ranging from strongly disagree, disagree, neutral, agree, to strongly agree, and scored 1, 2, 3, 4, and 5, respectively. The maximum possible total score for the KAB score was 30, and the minimum was 5. The scores were categorized into three groups: poor (scores between 5 and 10), fair (scores between 11 and 20), and good (scores between 21 and 30).
Normality was assessed through the Kolmogorov–Smirnov test and a normal Q-Q plot for the KAB score, diet recommendation score, and perceived factor scores. For all variables, the Kolmogorov–Smirnov test provided a non-significant alpha of
Chi-square and Mann–Whitney U-tests were used to compare weight status, diet characteristics, knowledge, attitudes, beliefs, perceived barriers, facilitators, and motivators between males and females. Spearman correlation and point biserial parametric tests were used to analyze the relationship between KAB score, weight status, and diet characteristics. Multiple regression analysis was used to analyze the influence of perceived barriers, facilitators, and motivators on dietary characteristics for female and male participants. Statistical significance was denoted by a
Table 1 illustrates the participants’ demographic characteristics. Nearly half of the participants were aged between 30 and 34 years (55.2%), and the other half was mainly comprised of participants aged between 35 and 44 years (27.9%). Additionally, most participants were Caucasian (60.7%), had a master’s degree (36.1%), earned an annual income greater than USD 100,000 (49.3%), and had a normal BMI (43.2%). A large proportion of males had a master’s degree (28.4%) and a high school diploma (21.6%), while most females had a master’s degree (38.4%) and a bachelor’s degree (23.9%).
Compared with female participants, a larger proportion of males were overweight or obese, (42.0%) and (39.8%), respectively. Only 28.0% of females were overweight, and 19.0% were obese. To determine whether the difference in male and female participants’ BMI was significant, a Mann–Whitney U-test was conducted. As shown in Table 1, male participants had a statistically significantly higher BMI (median = 3) than female participants (median = 2), Mann–Whitney U = 7,932.5,
Chi-square analyses were conducted to assess the differences in CRC diet recommendation scores between males (n = 88) and females (n = 289). As illustrated in Table 2, a larger proportion of females (65.1%) had significantly met the recommendation for sugary drinks as compared to males (35.2%), χ2 (1, n = 377) = 24.647,
To determine whether differences in nutrition knowledge scores exist between males (n = 88) and females (n = 289), Chi-square analyses were performed for each nutrition knowledge variable. As illustrated in Table 3, a large proportion of males (58%) and females (62.3%) were unaware of CRC frequent age occurrence. However, more than half of male and female participants responded correctly to all other nutrition knowledge questions. The Chi-square tests revealed no statistically significant differences in nutrition knowledge scores between males and females,
As illustrated in Figure 1, more than half of the participants (66.8%) believed a healthy diet was necessary to prevent CRC, and 79.3% of participants did not perceive diet as a futile solution to prevent CRC. In terms of behavioral beliefs, most participants agreed maintaining a healthy weight (86.2%), eating healthy (82.0%), and knowing CRC prevention guidelines (89.9%) were important. Similarly, a large proportion of participants (93.1%) acknowledged the severity of CRC regarding quality of life and death. Yet, 52.8% remained neutral regarding their perceived risk of developing CRC, and 30.8% believed they were not at risk of developing CRC.
Regarding perceived barriers, approximately 60% of participants did not perceive a need to quotidianly eat red meat (59.2%) and processed chicken (68.7%). Most participants (81.4%) disagreed that the taste of healthy foods was a hindrance, and 68.7% did not perceive time as a constraint to cooking. However, only 48.6% of the participants did not perceive healthy foods as costly. Nearly 60% of participants received recommendations from physicians (59.4%), friends, or family members (59.9%) about CRC, and 50.7% believed to know where to seek information about CRC. Finally, 45.1% agreed to regularly talk about their health to a health care provider. To determine differences in scores among males and females, Mann–Whitney U analyses were conducted. The results of the analyses are represented in Table 4. Males were significantly less cautious about their diet and the risk of developing CRC (mean rank = 168.12), as compared to females (mean rank = 195.36), U = 10,878.5,
Similarly, there were no differences between males (mean rank = 183.30) and females (mean rank = 188.75) regarding the variables addressing frequent intake of fiber, low fat, and low sugar, U = 12,023.0,
As per Table 4, the need to eat red meat was a more significant barrier for males (mean rank = 231.45) as compared to females (mean rank = 176.07), U = 8,980.5,
To assess whether a relationship existed between KAB scores and weight status among males and females, a Spearman analysis was conducted. As presented in Table 5, no relationship existed between BMI and KAB among males,
This study evaluated the differences in diet characteristics, weight status, nutrition knowledge, attitudes, and perceived beliefs among males and females to assess whether an association existed. The investigation revealed an overall good KAB level among participants despite poor diet recommendation adherence. Furthermore, the study reported significant differences between males and females regarding CRC diet recommendations, weight status, and perceived beliefs. These differences implied that males are exposed to higher CRC risk factors than females, yet females are not spared from the risks of developing CRC. These findings are important to develop nutrition initiatives focused on CRC prevention and behavioral changes among young and older adults. While nutrition education is fundamental, it may be ineffective for educated populations as discrepancies between nutrition knowledge, beliefs, and dietary recommendations existed among participants. Thus, the study suggests nutrition interventions designed to prevent CRC should acknowledge the differences in perceived beliefs among males and females. Nutrition interventions should also consider the factors influencing dietary behavior to improve health outcomes, especially among males.
A few studies that evaluated adherence to diet recommendations toward CRC have reported lower CRC risks among females  but higher risks among males . These findings are consistent with the results reported in this present study. Except for the alcoholic drink recommendation, most males did not meet the diet recommendations for preventing CRC. Whereas when compared with males, in addition to the alcoholic recommendation, females met the recommendations for sugary drinks and high caloric food. Interestingly, these results reflected participants’ weight status as males were more likely to be overweight or obese as compared to females. The adherence to the alcoholic drink recommendation was also observed in a previous study, but the study targeted CRC survivors .
Despite poor diet recommendation scores, results reported high levels of nutrition knowledge among participants. Though most participants were not aware of age as a risk factor for CRC, and most participants were indifferent in perceiving CRC as a susceptible risk during their lifetime. Studies that evaluated populations’ awareness regarding CRC explained such indifference by a need for improvement in medical awareness and population information about CRC risk factors [23,24]. Furthermore, modifiable risk factors of CRC, including poor diet and increased weight, were strongly associated with non-modifiable factors of CRC, such as age . Such modifiable risk factors must be altered to reduce CRC risk, especially among the populations with higher risk due to non-modifiable factors. In addition to age, sex was seen to be a potential risk factor for CRC, and males were deemed to be at higher risks due to high consumptions of meat and increased body weight . In consistency with these findings, this present study identified a higher BMI and meat consumption among males as compared with females.
Although a few differences in motivator and attitude scores existed, both males and females strongly acknowledged the implications of CRC regarding a decrease in quality of life and the importance of diet in CRC prevention. Paradoxically, the taste of healthy foods and the need to consume red meat and processed chicken were significant barriers for males. These findings are in line with those of a previous study in that males found healthful diets less appealing and were more tempted to eat processed foods . Love and Sulikowski  explained this paradox by revealing that males value meat more highly than women and perceive meat as healthy and delicious. These results indicate the potential existence of misconceptions among males regarding healthy eating. In contrast, females were more likely to be cautious about their diet and strongly considered the importance of acquiring nutrition knowledge to prevent CRC. Females perceived CRC severity as a motivator to improve their quality of life and were more likely to discuss healthful diets with their primary care physicians. Pool et al.  explained females are tempted to visit their physicians more frequently than males; such behavior may foster more opportunities to discuss diet.
As opposed to previous studies [29,30], in this study, most participants did not perceive the cost of healthy food products and time for cooking as barriers. This finding reiterates the notion of diet misconception and implies participants’ perceived beliefs may interfere with their food choices. Regardless of the differences between sex found in this study, participants had a good KAB level in that they had good nutrition knowledge, attitudes, and behavior. Surprisingly, no significant associations were observed between KAB and BMI. However, a significant association was found between KAB and meat recommendations only among overweight and obese males. These findings were consistent with the study of Acheampong and Haldeman , which did not report an association between KAB, BMI, and diet. As most participants met only one or two diet recommendations to prevent CRC, the results suggest that a good level of KAB may not be sufficient to influence healthy nutritional choices. Nonetheless, specific nutrition recommendations may foster dietary behavior improvements among overweight and obese individuals.
Acheampong and Haldeman  reported that overweight and obese participants had higher KAB scores and suggested that participants’ knowledge should be applied during their food selection process. The authors also recommended that health professionals develop nutrition initiatives based on populations’ beliefs . While education and beliefs are important elements, it is fundamental to consider all aspects of beliefs, including perceived barriers and facilitators. This study revealed that an increase in participants’ perceived barrier scores was significantly associated with a decrease in diet recommendations. Strangely, diet recommendation scores also decreased as facilitators increased. These findings suggest that further factors related to knowledge, beliefs, and attitudes may influence the use of facilitators. Individuals with good KAB levels, for instance, may not perceive a need for facilitators; consequently, they might unconsciously ignore their physicians’ recommendations or reject their friends’ and families’ advice regarding healthful diets. In studies exploring eating behaviors, facilitators including social support were positively associated with diet [8,16]. However, these studies focused on CRC survivors and only identified participants’ perceived facilitators. Consequently, it is unknown how populations follow and apply facilitators in the improvement of diet behavior.
The study presented several limitations. First, participants were not randomly selected because a convenience sampling method was used for their recruitment. Although such a method may be adequate, it is subject to sampling bias and can limit the generalization of the study. Additionally, the sample was homogeneous, consisting mostly of high-income Caucasian women. Therefore, the study is not generalizable to other populations, especially those living in low-income communities with more diverse ethnicities. Furthermore, as the study used a cross-sectional design, it cannot provide information regarding potential changes in dietary characteristics or attitudes over time. Finally, because participants self-reported their responses, accuracy might have been affected, and potential recall bias might have influenced data from the FFQ.
The differences in perceived beliefs between males and females indicate a need to design nutrition and health initiatives based on gender perceptions and specific unmet needs. The study suggests that health professionals should acknowledge the existence of misconceptions regarding healthy food to design population-centered nutrition initiatives for preventing CRC. Ultimately, perceived beliefs and dietary behavior may differ among more diverse populations living in different geographical areas. Thus, further studies using a randomized sample design should be conducted to assess the influence of socioeconomic and cultural factors on populations’ nutrition knowledge, weight status, and perceived beliefs.
This study revealed important points regarding nutrition and CRC prevention in that nutrition knowledge and KAB levels may not always reflect diet characteristics or weight status. Such inconsistencies may have emerged from misconceptions about healthy eating and may have influenced populations’ food choices. Further studies analyzing healthy eating misperceptions and food choices could help better understand the source of such misconceptions. Nonetheless, considering the differences between genders regarding nutritional beliefs and attitudes, the existence of misperceptions should be acknowledged in nutrition interventions focusing on CRC prevention. The present findings will provide health professionals with supplemental insights to design nutrition initiatives more centered on populations’ characteristics to reduce CRC prevalence.
I would like to express my gratitude to my primary supervisor, Dr. Tracy Matthews, who guided me throughout this research project. I wish to acknowledge the help provided by Dr. Anum Khurshid and all the volunteers who helped me during data collection. I thank the staff of the University Writing Center of A.T Still University for proofreading the manuscript, and finally, I would also like to thank my friends, coworkers, and family who supported me and offered extensive insights into the study.
No potential conflicts of interest were disclosed.
Sang Hoon Kim*, Jeong Yeon Moon*, Yun Jeong LimJ Cancer Prev 2022; 27(3): 139-146 https://doi.org/10.15430/JCP.2022.27.3.139
Soo In Choi, Nayoung Kim, Ryoung Hee Nam, Ji Hyun Park, Heewon Nho, Jeong Eun Yu, Chin-Hee Song, Sun Min Lee, Dong Ho LeeJ Cancer Prev 2021; 26(4): 277-288 https://doi.org/10.15430/JCP.2021.26.4.277
Johanna W. LampeJ Cancer Prev 2020; 25(2): 65-69 https://doi.org/10.15430/JCP.2020.25.2.65