Background: Poor diet and lack of physical activity can worsen cardiovascular health, yet most Americans do not meet diet and physical activity recommendations.
Purpose: To assist the U.S. Preventive Services Task Force in updating its previous recommendations by systematically reviewing trials of physical activity or dietary counseling to prevent cardiovascular disease.
Data Sources: MEDLINE, PsycINFO, Cochrane Central Register of Controlled Trials (2001 to January 2010), experts, and existing systematic reviews.
Study Selection: Two investigators independently reviewed 13 562 abstracts and 481 articles against a set of a priori inclusion criteria and critically appraised each study by using design-specific quality criteria.
Data Extraction and Analysis: Data from 73 studies (109 articles) were abstracted by one reviewer and checked by a second reviewer. Random-effects meta-analyses were conducted for multiple intermediate health and behavioral outcomes.
Data Synthesis: Long-term observational follow-up of intensive sodium reduction counseling showed a decrease in the incidence of cardiovascular disease; however, other direct evidence for reduction in disease morbidity is lacking. High-intensity dietary counseling, with or without physical activity counseling, resulted in changes of −0.3 to −0.7 kg/m2 in body mass index (adiposity), −1.5 mm Hg (95% CI, −0.9 to −2.1 mm Hg) in systolic blood pressure, −0.7 mm Hg (CI, −0.6 to −0.9 mm Hg) in diastolic pressure, −0.17 mmol/L (CI, −0.09 to −0.25 mmol/L) (−6.56 mg/dL [CI, −3.47 to −9.65 mg/dL]) in total cholesterol level, and −0.13 mmol/L (CI, −0.06 to −0.21 mmol/L) (−5.02 mg/dL [CI, −2.32 to −8.11 mg/dL]) in low-density lipoprotein cholesterol level. Medium- and high-intensity counseling resulted in moderate to large changes in self-reported dietary and physical activity behaviors.
Limitations: Meta-analyses for some outcomes had large statistical heterogeneity or evidence for publication bias. Only 11 trials followed outcomes beyond 12 months.
Conclusion: Counseling to improve diet or increase physical activity changed health behaviors and was associated with small improvements in adiposity, blood pressure, and lipid levels.
Primary Funding Source: Agency for Healthcare Research and Quality.