Behavior change has become a central objective of public health interventions, with an increased focus on prevention in health services at many levels. This is seen as particularly important in low and middle income countries, where the efficiency of health spending and the costs and benefits of health interventions has been under increased scrutiny in recent decades Many health conditions are caused by risk behaviors, such as problem drinking, substance use, smoking, reckless driving, overeating, or unprotected sexual intercourse. The key question in health behavior research is how to predict and modify the adoption and maintenance of health behaviors. Fortunately, human beings have, in principle, control over their conduct. Health-compromising behaviors can be eliminated by self-regulatory efforts, and health-enhancing behaviors can be adopted instead, such as physical exercise, weight control, preventive nutrition, dental hygiene, condom use, or accident prevention. Health behavior change refers to the motivational, volitional, and actional processes of abandoning such health-compromising behaviors in favor of adopting and maintaining health-enhancing behaviors. Behavior change programs, which have evolved over time, encompass a broad range of activities and approaches, which focus on the individual, community, and environmental influences on behavior. Behavior change, a relatively recent public health-related term, should not be confused with behavior modification, a term with specific meaning in a clinical psychiatry setting. Behavior change programs tend to focus on a few behavioral change theories which gained ground in the 1980s. These theories share a major commonality in defining individual actions as the locus of change. Behavior change programs that are usually focused on activities that help a person or a community to reflect upon their risk behaviors and change them to reduce their risk and vulnerability are known as interventions. See also “The Transtheoretical (Stages of Change) Model of Behavior Change,” “The Theory of Reasoned Action,” “The Health Belief Model” and the Health Action Process Approach.