Intention can be a poor predictor of actual health behavior change—now termed the intention-behavior gap. In other words, although patients intend to change and maintain their behavior, the data suggest that many will not follow through with their intention. This review introduces 5 factors that could help the practitioner understand the patient intention-behavior gap: (1) the motivation, (2) the trigger, (3) the response, (4) the capacity, and (4) the process. These key factors allow the lifestyle medicine practitioner to (1) understand the difficulties in changing patient behavior and (2) apply strategies to encourage successful change and maintenance of healthy lifestyle behavior in their patients.