Perspectives on Intervening on Physical Inactivity and Diet

The global epidemic of obesity is staggering in its scope. The World Health Organization (2011) reports that nearly 1.5 billion adults aged 20 years and older and 43 million children younger than 5 years are overweight. The health, societal, and economic impact of obesity on current and future generations is daunting. Obesity is associated with an increased prevalence of serious chronic diseases and conditions, including cardiovascular diseases, diabetes mellitus, cancer, musculoskeletal conditions, mental health disorders, and physical function limitations and disability (Abdullah et al., 2011; Alley & Chang, 2007; Deaton et al., 2011; Martin, Freedman, Schoeni, & Andreski, 2010; Wang, McPherson, Marsh, Gortmaker, & Brown, 2011).

Obesity among participants 30 to 49 years old in the Framingham Study was associated with a doubling of probability of having a physical function limitation in older age (Peeters, Bonneux, Nusselder, De Laet, & Barendregt, 2004). Available data on direct health care costs estimate that obesity accounts for 74 billion dollars of all health care expenditures in the United States and 33 billion euros in the European Union and 25% of all health expenditures in Canada (Allender, Foster, Scarborough, & Rayner, 2007; Anis et al., 2010; Trasande & Elbel, 2012). An additional 5.5 billion British sterling pounds in health care expenditures associated with obesity are projected by 2050 in the United Kingdom (Trasande & Elbel, 2012; Wang et al., 2011).

Physical inactivity and poor dietary habits are the primary contributors to overweight and obesity. Individually, physical inactivity and poor dietary habits increase the risks of developing many chronic diseases and conditions—and these risks are compounded in the presence of obesity (U.S. Department of Health and Human Services, 2008; World Health Organization, 2011, 2012). Physical inactivity and unhealthy dietary habits are highly prevalent in developed and—increasingly so—in developing countries throughout the world (World Health Organization, 2008, 2011).

The body of scientific literature about physical activity and diet has grown exponentially over the past decade, demonstrated by the sheer volume of published articles in this and other journals. However, the effectiveness of long-term interventions to promote physical activity has been equivocal, but shorter term interventions have shown some success in improving physical activity (Garber et al., 2011). Obesity prevention and treatment programs have been effective in children (Oude Luttikhuis et al., 2009; Waters et al., 2011) but somewhat less so in adults (Appel et al., 2011; Wing & Phelan, 2005). Thus, there remains much to learn about these complex behaviors and how to effectively intervene in diverse settings and populations.

This issue of Health Education & Behavior carries a thought-provoking collection of studies about physical activity and diet, which advances knowledge about these behaviors and provides some intriguing and potentially promising models for intervention. Hereditary, environmental, and behavioral factors influencing diet or physical activity behaviors were identified in several studies. Beaver, Flores, Boutwell, and Gibson (2012) uncovered evidence of genetic contributions to eating behaviors in pairs of adolescent sibling participants in the National Longitudinal Study of Adolescent Health. Gender differences in the environmental factors influencing whether or not a child walked to school were found by Trappe et al. (2012). Koring et al. (2012) reported that self-efficacy was a mediator between intentions for engaging in physical activity and planning for physical activity.

There are also some innovative school-based intervention studies reported in this issue. School garden programs enhanced children’s willingness to try vegetables, enjoyment of the taste of vegetables, socialization and quality of life (Jaenke et al., 2012). An after-school program to provide a reimbursable, healthy after-school snack to middle school students was found to be feasible (Nanney, Olaleye, & Wang, 2012).

Some articles reporting on interventions in adults also give pause. Dissemination of a physical activity intervention in communities by trained volunteers was feasible and effective in improving physical fitness in older people (Seguin, Heidkamp-Young, Kuder, & Nelson, 2012). A review by Hendrie et al. (2012) found that effective interventions used more behavior change techniques than ineffective interventions and that these included methods such as providing general information, prompting behavioral practice, planning for social support, and social changes.

These reports raise provocative questions for the work of health education specialists and other professionals: How do we address the interactions between genetics, the environment and the individual when designing interventions? How can we integrate programs such as those presented here into the schools as essential components of the curriculum? These issues point to the need for a well–thought out hypothesized model of effect as to which variable(s) to choose to investigate. To guide how to use theory appropriately, there is a “litmus test” (Nigg & Paxton, 2008) available, which includes the concepts presented below. This litmus test is presented in full, not only as a useful guide for planning a program or intervention but also as informative notes when one is evaluating interventions. Being aware of these items when planning programs or interventions will ensure a more thorough approach, decrease the likelihood of missing important components, and provide a more informative evaluation.

The use of trained volunteers to provide the services usually provided by professionals is another issue to contemplate. The model of training volunteers to deliver health promotion programming presented in the study by Seguin, Heidkamp-Young, Kuder, and Nelson (2012) is an attractive, apparently low-cost way to reach the large numbers in the population who can benefit from physical activity. On the other hand, this study raises a serious question as to whether or not advocating the use of volunteers to deliver services that are often provided by professionals is advisable. Exercise physiology and health education are still-emerging professions, and there are many current and recent trainees who are looking for employment. These professions possess an expressed set of knowledge, skills and competencies, and trained professionals who are able to apply evidence-based evaluations and interventions—and who can adapt these according to group and individual characteristics, health conditions, and other factors. Thus, at the same time, when preferentially promoting volunteer workers to deliver programs, we might be undermining the professional workforce. A model in which well-trained professional workers provide training and supervision for less well-trained professional and lay workers may be a viable and sustainable alternative, as long as there is commitment and the ability to fund the supervisory staff that does not provide direct services.

The articles in this issue contribute to our understanding about conducting successful interventions, but much work remains to be done to address health behaviors that contribute heavily to the global burden of obesity and chronic disease. The urgency to act is becoming a global priority. A recent high-level meeting on the prevention and control of noncommunicable diseases at the United Nations (Probst-Hensch, Tanner, Kessler, Burri, & Kunzli, 2011), declared in part, “[We] Recognize that the most prominent non-communicable diseases are linked to common risk factors, namely tobacco use, harmful use of alcohol, an unhealthy diet, and lack of physical activity . . .” (United Nations General Assembly, 2011).

This leads to another area of opportunity; namely multiple health behavior change (MHBC) research. This kind of research involves intervening on two or more health behaviors either simultaneously or sequentially within a limited time period (J. J. Prochaska, Nigg, Spring, Velicer, & Prochaska, 2010; J. O. Prochaska, 2008). Conventional wisdom has been that it is not possible to treat multiple behaviors simultaneously, because it is too burdensome and places too many demands on a person’s inherent ability to change (Johnson et al., 2008). However, MHBC interventions for a common health objective, for example, cancer prevention, diabetes self-management, or weight management, have shown significant impact on multiple behavior changes (Lippke, Nigg, & Maddock, 2011; Mays et al., 2011; Toobert, Strycker, Barrera, et al., 2011; Toobert, Strycker, King, et al., 2011).

MHBC interventions incorporate the covariation/coaction principle by which individuals taking effective action on one target behavior are more likely to take effective action on a second behavior and are likely to take effective action on untreated behaviors related to the treated behaviors (Blissmer et al., 2010; J. O. Prochaska, 2008). Moreover, successful change in one or more health behavior may increase self-efficacy for another behavior in those with a lower motivation to change (J. O. Prochaska, 2008). This is related to the concept of a gateway behavior (Patterson, 2001) where one health behavior change leads to other behavioral change. In addition, MHBC interventions may have more real-world applicability and provide strategies for behaviors that co-occur (J. J. Prochaska et al., 2010).

It is encouraging that there is increased attention by policy makers, professionals, and the public, but we all need to engage in these conversations to sustain serious action. However, there are many gaps in our understanding of these behaviors, and effective tools intervene, so we cannot let up in our efforts to conduct and publish innovative, high-quality, theory-driven research. Finally, we must promote translation and dissemination of effective research interventions to real-life settings. We are more likely to be successful using a multipronged approach to the problems, combining advocacy and policy, with research, translation, and dissemination. We cannot afford not to try, as the consequences are too great. Fortu- nately, the articles contained in this issue help point the way.