Commentary
Because health behaviors are critical in areas such as prevention, treatment, and rehabilitation, it is important to describe and understand what drives these behaviors.1 Theories are important tools in this effort as they aim to explain and predict health behavior and are used in the design and evaluation of interventions.1 The TPB is one of the most widely accepted behavior change theories and posits that attitudes, subjective norms (or social pressures and behaviors), and perceived behavioral control are significant predictors of an individual’s intention to engage in behaviors.2 TPB has been highlighted in the literature as a validated theory for predicting nutrition and PA intentions and resulting behaviors.3,4
Motivating lifestyle behavior change in clinical practice can be challenging, but some studies have demonstrated how providing genetic information and advice (or lifestyle genomics) can help motivate changes in nutrition and PA among patients.5-7 Because this has yet to be explained using the TPB, this study is an important contribution to the literature as it aimed to determine the impact of providing genetically tailored and population-based lifestyle advice for weight management on key constructs of the TPB. Briefly, results from within-group analyses in this study demonstrated that the provision of genetically tailored lifestyle information and advice (via the GLB+LGx intervention) tended to impact antecedents of behavior change, more so over the long-term, while population-based advice (via the standard GLB intervention) tended to impact antecedents of behavior change over the short-term (eg, attitudes towards dietary fat intake, perceptions that friends and family consume a healthy diet, and perceptions about the impact of genetic-based advice for weight management). In addition, between-group differences in subjective norms observed at 12 months suggested that social pressures and norms may be influencing long-term changes in lifestyle habits.
While key strengths of this study include its pragmatic cluster randomized controlled trial design, 12-month intervention duration, and intent-to-treat analyses, there are some study limitations, which are acknowledged by the authors. Generalizability is limited to the demographic characteristics of the study population (ie, middle-aged, middle-income, Caucasian females enrolled in a lifestyle change weight management program). Thus, replication of the study is needed in more diverse study populations and with health-related outcomes beyond weight management. In addition, as the authors indicate, future research should ensure the inclusion of theory-based questionnaires in genetic-based intervention studies assessing lifestyle behavior change to elucidate theory-based mechanisms of change.
Applications for Clinical Practice
Population-based research has consistently indicated that nutrition interventions typically impact short-term dietary changes. Confronting the challenge of long-term adherence to nutrition and PA recommendations requires an understanding of factors impacting long-term motivation and behavior change. With increased attention on and research into genetically tailored lifestyle advice (or lifestyle genomics), it is important for clinical practitioners to be familiar with the evidence supporting these approaches. In addition, this research highlights the need to consider individual factors (attitudes, subjective norms, and perceived behavioral control) that may predict successful change in lifestyle habits when providing nutrition and PA recommendations, whether population-based or genetically tailored.
—Katrina F. Mateo, PhD, MPH