Health Behavior Change and Intervention

Health behavior change concerns how people start, maintain, or stop behaviors that affect their health — such as physical activity, diet, smoking, alcohol use, and adherence to treatment — and how interventions can support such change. It draws on psychological theories of motivation and self-regulation and increasingly specifies interventions in terms of replicable 'behavior change techniques'.

Definition

Health behavior change is the study and practice of modifying health-relevant behaviors through theory-informed interventions, often described as combinations of standardized behavior change techniques targeting determinants such as motivation, intention, self-efficacy, and self-regulation.

Scope

This entry covers the major theories of health behavior, the concept of behavior change techniques and their classification, and the principles of designing and evaluating behavior change interventions. It treats the subject as a reference topic in clinical health psychology and does not prescribe specific programs or individual behavior plans.

Core questions

• What psychological factors determine whether people adopt and maintain healthy behaviors?
• Which intervention components (behavior change techniques) are effective and for whom?
• How can interventions be described precisely enough to be replicated and compared?
• How do individual, social, and environmental influences interact in shaping behavior?

Key concepts

• Behavior change techniques (BCTs)
• Self-efficacy
• Intention and motivation
• Self-regulation and goal setting
• Intervention fidelity and replicability
• Determinants of health behavior

Key theories

Theory of planned behavior

Ajzen's model in which behavior is predicted by intention, which in turn is shaped by attitudes, subjective norms, and perceived behavioral control; widely used to explain and target health behaviors.

Transtheoretical (stages of change) model

Prochaska and DiClemente's account of behavior change as movement through stages — from precontemplation to maintenance — with different processes salient at each stage.

Mechanisms

Behavior change interventions are understood as acting on the psychological determinants of behavior — such as intentions, self-efficacy, outcome expectancies, and self-regulatory skills — specified by underlying theory. The behavior change technique taxonomies of Abraham and Michie and the later CALO-RE work provide a shared vocabulary for the active ingredients of interventions (for example goal setting, self-monitoring, feedback, and prompting), so that interventions can be described, replicated, and compared. Glanz and Bishop document how behavioral science theory informs the design and implementation of public health interventions.

Clinical relevance

Behavior change theory and intervention design inform health-promotion programs, lifestyle and adherence support, and the behavioral components of chronic-disease management across health-care settings. This entry summarizes concepts and evidence for reference and does not constitute a prescription of specific interventions for any individual.

Evidence & guidelines

The evidence base includes randomized trials and systematic reviews of behavior change interventions across domains such as physical activity, diet, and smoking, supported by taxonomic work that standardizes how intervention content is reported. Theory-based reviews link behavioral science to intervention design and implementation.

History

Early health behavior research was dominated by social-cognitive theories such as the theory of planned behavior and the transtheoretical model, which sought to explain why people do or do not act on health information. From the 2000s onward, the field shifted toward specifying interventions themselves, producing behavior change technique taxonomies (Abraham and Michie 2008; the CALO-RE taxonomy 2011) that made intervention content explicit and reproducible.

Debates

How well do social-cognitive models predict actual behavior?

Models such as the theory of planned behavior explain intentions better than they explain behavior, and the gap between intention and action has prompted greater emphasis on self-regulatory and implementation processes.

Key figures

• Susan Michie
• Charles Abraham
• Icek Ajzen
• James O. Prochaska
• Karen Glanz

Seminal works

• abraham-michie-2008
• ajzen-1991
• prochaska-diclemente-1983

Frequently asked questions

What is a behavior change technique?

It is the smallest identifiable, replicable component of an intervention designed to change behavior — for example goal setting, self-monitoring, or feedback — standardized in taxonomies so interventions can be described and compared consistently.

Why do people often fail to act on healthy intentions?

Research shows that intentions predict behavior only modestly; translating intention into action depends on self-regulatory skills, habits, and environmental supports, which is why modern interventions target these as well as motivation.