NC1193: Assessing and addressing individual and environmental factors that influence eating behavior of young adults
Statement of Issues and Justification
STATEMENT OF THE PROBLEM: Excessive weight gain is associated with increased risk of developing many serious diseases, including cardiovascular disease, hypertension, and type 2 diabetes. Young adults are at a uniquely increased risk for weight gain because of rapidly changing social situations that influence eating and exercise behaviors. Despite extensive efforts to promote weight management, these efforts only reach a small proportion of the population at risk and even effective programs promoting individual behavior change may have limited effectiveness in environments that promote weight gain. Research is needed to elucidate the combination of individual and environmental factors associated with unhealthy weight gain among college students.Participants in this multi-state research group have applied theory-based behavioral constructs to design intervention programs to promote healthful eating and exercise behaviors in young adults with a goal of preventing unhealthy weight gain. Although these programs have been effective in improving dietary behavior, they did not prevent weight gain. The previous five years of this multi-state research have been devoted to building community relationships with young adults using principles of community-based participatory research. The results of this work have led to the identification of environmental and behavioral barriers and facilitators, and to the development of instruments for assessing environmental and individual factors associated with health outcomes such as body weight. The purpose of this renewal is to refine and validate these instruments and to define the relationship between environmental and behavioral factors with a goal of quantifying these to create a Healthy Campus Index. JUSTIFICATION: Although the dramatic increases in rates of obesity may be leveling off, obesity is still at epidemic proportions in the U.S. (Flegal et al., 2010). As of 2004, 66.3% of adults (61.8% female and 70.8% male) in the U.S. were overweight or obese and 32.2% were obese (33% female and 31% male) (Ogden et al., 2006). Obesity contributes to the major causes of premature death in the U.S., with an estimated 300,000 deaths per year attributable (Allison et al., 1999) and is an important independent risk factor for atherosclerotic cardiovascular disease, type 2 diabetes, stroke, some forms of cancer, breathing problems, arthritis, reproductive complications and psychological disorders, such as depression. (Calle et al., 2003; Murphy et al., 2000).
Young Adults and Obesity. Young adults, aged 18-25, are at especially high risk for weight gain (Lewis et al. 2000; Klem, 2000). For many college students weight gain begins during their freshman year. Lloyd-Richardson et al. (2009) collected height and weight data from college freshmen and followed many of them through their sophomore year. Data were collected from two universities: one public and one private. During their freshman year, 77% of student participants from the public university gained weight (3.5 kg for men and women). Seventy percent of the students from the private university gained weight (2.5 kg for men and 1.6 kg for women). Most of the weight gain from both schools occurred during the first semester. Although many of the students still had a healthy body mass index (BMI) after the weight gain, rates of overweight/obesity increased from 22% to 36% in the public university and 15 to 18% in the private university. Students from the public university were followed through their sophomore year, and total weight gain for both years was 4.3 kg for men and 4.2 kg for women. Racette et al. (2005) reported similar findings from a longitudinal study to assess weight changes during freshman and sophomore years of college where 70% of the students had gained approximately 4.1 kg by the end of their sophomore year. Morrow et al. (2006) reported an increase in weight gain between fall and spring semesters of approximately 1.1 kg among freshman women during their first year of college.
The weight gain observed in the studies above may be due to the many different changes that occur in the lives of young adults. Many are transitioning into independent living and residing on college campuses where they are not making healthful choices as evidenced by The American College Health Association National College Health Assessment (ACHA-NCHA),. This assessment collects information on a broad range of student health behavior, health indicators, and perceptions. The Fall 2009 Reference Group includes ACHA-NCHA data from 34,208 students at 57 institutions of higher learning. Only 5.9% of college students (n=2,018) ate five or more servings of fruits and vegetables daily. Less than half met the recommendations for exercising vigorously for at least 20 minutes on three or more days per week or moderately for at least 30 minutes on five or more days per week (American College of Health Association, 2007). These negative health behaviors may be associated with the weight gain observed for young adults after entering college. This may be especially important for health because being overweight between the ages of 20-22 years is associated with an increased risk of obesity at 35-37 years of age (McTigue et al., 2002; Guo et al., 2000).
Many of these young adults will become, or are, parents. Parents dietary quality influences their childrens dietary quality: parents who are overweight or obese are more likely to have children who are overweight or obese. Given the concern with childhood obesity, it is important to target the young adult population to improve the young adults diet and weight management skills. Thus, weight management interventions with young adults may be important in preventing negative health conditions that may have deleterious lifelong health consequences for both the young adult and the next generation of young children.
Dietary Behavior Associated with Weight Management. Dietary behavior associated with weight management needs to be better understood. Weight gain results from chronic positive energy balance related to dietary and exercise behaviors (U.S. Food and Drug Administration, 2004); however, the underlying causes of overweight and obesity are multidimensional (Kumanyika & Obarzanek, 2003; U.S. Food and Drug Administration, 2004)
Specific food consumption behaviors have been associated with increased weight. For example, women who reported eating out a greater number of times per week also reported greater total energy intake and consumed a poorer-quality diet (Clemens et al., 1999). The frequency of consuming restaurant food also has been positively associated with increased body fat percentage in adults (McCrory et al., 1999). Using a multivariate model and data collected from the Health Risk Appraisal administered on a college campus, Adams and Rini (2007) reported that increases in BMI in women were associated with low intake in cruciferous vegetables and fiber, and high intakes of cholesterol-containing food and alcohol.
Individualized Factors and Obesity. There are many individualized factors that may play a role in eating behavior and the development of obesity. These factors include (but are not limited to): personality, parental status, income level, ethnicity, within-meal eating behavior, cognitive behavioral influences, and interpersonal influence susceptibility.
Personality. One way in which interventions may be customized is to tailor interventions for individuals based on personality characteristics. Elfhag and Rossner (2005) indicate that factors like possession of coping skills, presence of self-efficacy, and being a healthy narcissist are associated with success in losing weight, while characteristics such as disinhibited eating, perception of weight loss barriers, and psychosocial stressors can lead to weight gain.
Parental status. Parental obesity has been associated with higher risk for childhood obesity in cross-sectional (Danielzik et al.,2002; Sekine et al., 2002; Plachta-Danielzik et al., 2010; Whitaker et al., 2010) and longitudinal studies (Dubois and Girard, 2006). Recently, Whitaker et al. (2010) assessed the effect of maternal and paternal weight status individually and combined on risk for obesity in 7078 children in the UK. The incidence of obesity in children from families with two obese parents was 21.7% compared to 2.3% from families with two normal weight parents. In addition, children with two obese parents were 12 times more likely to be obese than children with normal weight parents. When obese parents were further stratified by severity of obesity, children with two severely obese parents were 22 times more likely to be obese than children of normal weight parents. Parental obesity has also been associated with more rapid weight gain between ages three and five (Griffiths et al., 2010), which may increase the risk of obesity in later childhood (Cole, 2004).
Income level. The association of low income levels with mortality related to obesity was found to be strong after controlling for major behavior risks in a 19-year prospective study of U.S. adults (Lantz et al., 2010). Obesity is more common among the less affluent, especially for the female population (Nikolaou and Nikolaou, 2008). Obesity rates were found to increase in females over time as neighborhood-level incomes decreased (Black and Macinko, 2010). Effective obesity preventive health policies need to consider individual and contextual determinants of obesity such as income levels.
Ethnicity. There are disparities in obesity prevalence among different ethnicities. According to NHANES 2007-2008 non-Hispanic black adults had the highest prevalence of obesity at 44% followed by Mexican Americans at 40 %, all Hispanics at 39 % and non-Hispanic whites at 32 % (Flegal et al., 2010). Within racial groups also had disparities by gender. Non-Hispanic black women consistently had a higher prevalence of obesity than non-Hispanic black men (52.9% vs. 37.2%, respectively, in NHANES 2005-2006 and 49.6% vs. 37.3%, respectively, in NHANES 2007-2008) (Flegal et al., 2010; Ogden, 2009). In children racial and ethnic differences in the prevalence of obesity also exist. According to data from NHANES 2007-2008, the percentage of obesity and overweight and obesity combined in children 2 to 19 years of age was 20% and 35.9 % in non-Hispanic blacks, 20.8% and 38.9 % in Mexican Americans, 20.9% and 38.2 % in all Hispanics and 15.3% and 29.3 % in non-Hispanic whites. Hispanic boys had a significantly higher risk of obesity than non-Hispanic white boys. Non-Hispanic black girls had a significantly higher risk of obesity than non-Hispanic white girls (Ogden et al., 2010). The differences among racial groups may be explained by cultural influences on physical activity and family attitudes about food and eating, as well as access to healthful foods and physical activity facilities, which may promote weight gain.
Within-Meal Eating Behavior. Based on accumulating evidence, within-meal eating behavior, such as eating rate, bite size, chewing, oro-sensory processing, attentiveness to the development of satiation, and meal termination, have important implications in energy intake and body weight regulation (Westerterp-Plantenga, 2000; Laessle et al., 2007; Andrade et al., 2008; Llewellyn et al., 2008). Researchers of population-based studies have supported relationships between eating rates and body weight (Takayama et al., 2002; Otsuka et al., 2006; Sasaki et al., 2003; Greene et al., 2008). Independent effects have also been demonstrated between eating rate and insulin resistance (Otsuka et al., 2008), and components of metabolic syndrome (Kral et al., 2001).
Cognitive Behavioral Influences. Eating and exercise behavior, as well as attitudes towards weight status and related psychosocial determinants of weight differ by sex (Connor-Greene, 1988; Zmijewski and Howard, 2003; Mackey and La Greca, 2007). College-aged males tend to want to gain weight by building muscle, whereas females desire to lose weight (Connor-Greene, 1988; Neighbors and Sobal, 2007). Females are more likely to have higher dietary restraint and emotional eating scores relative to males (de Lauzon et al., 2004), indicative of problem eating behaviors that could lead to disordered eating (Lindeman and Stark, 2001) and/or weight gain (Hill and Peters, 1998). Specific patterns of psychosocial and behavioral variables were found in college students at elevated health risk (Greene et al., in press). Despite these differences, Economos and colleagues found weight gain in the freshman year did not differ by sex (Economos et al., 2008).
Interpersonal Influence Susceptibility. Research by Greaney, Less, White, Dayton, Riebe, Blissmer, Shoff, Walsh, & Greene (2009) implicated eating out with others as an interpersonal barrier for weight management faced by college students. The same research by Greavey et al. (2009) identified social support as a crucial factor for female college students more so than male college students for healthy eating. For some female college students, eating with a friend can result in eating more than if they ate with a stranger (Koh and Pliner. 2009). Not all college students may be equally influenced by social situations. To better understand the reasons why people make the food choices they do Rothman, Gillespie, & Johnson-Askew (2009) recommended that interpersonal behaviors be further studied.
The concept of personal food systems investigates how and why food decisions are made in different situations. According to research by Connors, Bisogni, Sobal and Devine (2001), food decisions are influenced by the maintenance of socially acceptable food choices and the values that groups and their members place on foods. Therefore, the food choice decisions college students make could depend on their social environment. The life course perspective (LCP) which has been used to examine factors related to health status over time can be used to explore the connection between peer social groups and the food decisions made by their members.
With its roots in sociology, LCP can be used to examine relationships between both family members and peers. One life change that could be studied is the time period when a young adult starts and attends college. Research by Vermeir and Verbeke (2006) has shown that a persons social network influences food choices. Understanding the influence that college students social groups have in different contexts could help to develop interventions to improve the nutritional status of groups of college students.
Environmental Factors and Obesity. The impact of the built environment on risk for obesity is pervasive in the obesity literature. The built environment encompasses a variety of components including, but not limited to, neighborhood walkability, access to parks, safety, cleanliness, and traffic flow (Renalds et al., 2010). These factors influence the ability and desire for people to be physically active. A review by Renalds et al. (2010) identified factors of the built environment that influenced physical activity. More lights, fewer intersections and traffic, and better scenery all encouraged physical activity, while poor security and poor neighborhood maintenance discouraged physical activity. The authors concluded that neighborhoods that encouraged walking had more physically activity residents with lower incidence of overweight. Many researchers have reported a positive association between some aspect of the built environment and obesity (Giles-Corti et al., 2003; Booth et. al, 2005; Papas et al., 2007; Timperio et al., 2010), possibly because of barriers to physical activity. In their review on obesity and the built environment, Booth et al. (2005) note that biological, psychological, behavioral, and social factors do not fully account for the current obesity epidemic, which provides support for the evaluation of the effect of the built environment. Increasing the ability for neighborhoods to promote physical activity may translate into a reduced risk for obesity but may be a challenge in socially disadvantaged neighborhoods where physical activity is lower for a variety of reasons (Giles-Corti and Donovan, 2002; Cerin and Leslie, 2008; Turrell et al., 2010). More affluent neighborhoods tend to have higher levels of physical activity, which may provide more protection against certain diseases in these communities (Turrell et al., 2010).
Currently there are few published studies documenting the effect a change in the built environment has had on the community. McCreedy and Leslie (2009) described a city-wide initiative in Orlando, Florida, called Get Active Orlando that brought together a multidisciplinary team of community partners passionate about changing the culture of their city to encourage physical activity. With a grant from the Robert Wood Johnsons Active Living by Design initiative, researchers designed and implemented a community-wide campaign that encouraged healthful lifestyle changes. After establishing baseline data by surveying their target low socioeconomic status neighborhood, researchers developed programs designed to increase physical activity such as bike giveaways, safe bike rides, free bike repair, a senior walking program, and a community garden. These programs were successful in getting the community involved and physically active. The program successes have led to policy changes for development projects in the community intended to make the city more active. Their website (www.getactiveorlando.com) provides information as well as a Design Standards Checklist to be used by developers to promote physical activity in developments. A similar program in Somerville, Massachusetts, (Burke et al., 2009) also achieved positive results. Although it is premature to determine if changes in the built environment will lead to a decrease in obesity, Orlando and Somerville can serve as models for community promotion of physical activity for the health benefit of residents.
Another environmental factor is the food environment. According to Hill and Peters (1998) one way in which the current environment promotes obesity is by providing more frequent opportunities for the consumption of large quantities of food. A variety of highly palatable, inexpensive foods is available nearly everywhere. A cross-sectional survey of rural adults indicated that frequency of eating at establishments that promote excessive food consumption such as buffets, cafeterias and fast food was positively associated with obesity (Casey et al., 2008). Young adults in the Coronary Artery Risk Development in Young Adults (CARDIA) study who ate at fast food restaurants more than twice a week had a significantly higher weight gain during the 15 year study period than those who ate fast food less than once a week (Pereira et al., 2005). Despite these positive associations, a recent review of the literature indicates insufficient evidence to support an association between fast food consumption and obesity, and more studies are needed (Giskes et al., 2007). School Health Index. The Center for Disease Control has published manuals and guidelines for School Health Indexes for elementary (Center for Disease Control, 2005a), middle, and high schools (Center for Disease Control, 2005b). These School Health Indexes (SHI) are self-assessment and planning guides that involve teachers, parents, students and the community involvement in the process of identifying the strengths and weaknesses of the schools policies and programs for promoting health and safety and development of an action plan for improvement in these areas. The health topics assessed through this index include physical activity and physical education, nutrition, tobacco use prevention, asthma, and safety prevention. These indexes can be used by the schools for needs assessment, prioritization of needs, and implementation of prevention programs (Sherwood-Puzzello et al., 2007). There is no index currently available for higher education campuses.
By recognizing that a myriad of environmental and individualized factors can influence eating behavior and lifestyle choices, tailored intervention strategies that have both an environmental and individual focus can begin to be developed. Additionally, identification of the individual factors and the necessary environmental factors to support the individual change is the first step in the development of indexes for comparisons and benchmarking to support policies and programs for behavior change on college campuses and communities.
Benefits of this project: This proposed research will continue to use the community-based participatory research (CBPR) design. Research investigators will continue to work side-by-side as partners with young adults to understand, develop, create, and tailor interventions desired by young adults. By using these CBPR approaches, results of this work are more likely to be effective. Grant funding will be pursued for this participatory research and for the resulting tailored intervention projects, as well as smaller state/local specific projects. The ultimate outcome of this work will be tailored intervention strategies and environmental support approaches that meet the young adult groups needs in their acquisition of healthful eating behavior to prevent excessive weight gain. These improvements in young adults eating behavior will likely also affect the eating behavior of young adults current and future young children. The collective power of the multiple states collaborating throughout the entire participatory process will significantly contribute to the understanding of how to best meet young adults needs as they strive to prevent weight gain and adopt healthful habits. The outcomes from this work address health promotion priorities of USDA and other agencies such as NIH and the Institute of Medicine.
Need for cooperative work: Because of the multidimensional etiology of obesity and the equally multidimensional intervention designs needed to reduce incidence of obesity, significant large-scale progress toward weight management is unlikely to be achieved by a single investigator or University location; even the National Institutes of Health acknowledges this point. Thus, a multi-state research team approach will increase diversity of expertise, environmental locations, and population demographics. The procedures outlined in this proposal require an enormous amount of work and a diverse set of research skills, all factors that this research team can provide. Furthermore, the limitations of previous studies on how environmental factors affect diet quality and health have suffered from regional bias that restricts ability to generalize findings. By using multiple campuses to address specific objectives, this research team will be able to not only increase the power of analyses, but also enhance applicability of the findings and resolve regional disparities.
This effective collaborative research relationship is demonstrated through a strong publication record with multiple authors from different institutions. This multi-state research team has a strong record of collaborative research (NC200, NC219, NC219R, and NC1028 multi-state research) that will allow diversity needs to be met. Additionally, this research collaborative has successfully secured USDA grant funding, including an Initiative for Future Agriculture and Food Systems (IFAFS) grant and three National Research Initiative (NRI) grants.
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