Interventions to Promote Physical Activity and Dietary Lifestyle Changes for Cardiovascular Risk Factor Reduction in Adults

Approximately 79 400 000 American adults, or 1 in 3, have cardiovascular disease (CVD).¹ CVD accounts for 36.3% or 1 of every 2.8 deaths in the United States and is the leading cause of death among both men and women in the United States, killing an average of 1 American every 37 seconds.¹ Older adults, some ethnic minority populations, and socioeconomically disadvantaged individuals have an increased prevalence of CVD and vascular/metabolic risk factors such as hypertension, dyslipidemia, and diabetes; are more likely to have ≥2 risk factors; and are at increased risk of being sedentary, overweight or obese, and having unhealthy dietary habits.^2–10 Black and Hispanic immigrants are initially at lower risk for vascular/metabolic risk factors and CVD than US-born black and Hispanic individuals,² but as they adapt to the diet and activity habits of this country, the prevalence of vascular/metabolic risk factors increases.³ Each of these issues emphasizes the importance of interventions to promote physical activity (PA) and healthy diets in all American adults.

Even modest sustained lifestyle changes can substantially reduce CVD morbidity and mortality. Because many of the beneficial effects of lifestyle changes accrue over time, long-term adherence maximizes individual and population benefits. Interventions targeting dietary patterns, weight reduction, and new PA habits often result in impressive rates of initial behavior changes, but frequently are not translated into long-term behavioral maintenance.⁴ Both adoption and maintenance of new cardiovascular risk-reducing behaviors pose challenges for many individuals. According to the National Center for Health Statistics, life expectancy could increase by almost 7 years if all forms of major CVD were eliminated.⁵ Improvements in morbidity and quality of life would also be substantial. In order to achieve these goals, healthcare providers must focus on reducing CVD risk factors such as overweight and obesity, poor dietary habits, and physical inactivity by helping individuals begin and maintain dietary and PA changes. Each year >$44 billion, including $33 billion in medical costs and $9 billion in lost productivity due to heart disease, cancer, stroke, and diabetes, is attributable to poor nutrition.⁶ In the year 2000, the annual estimated direct medical cost of physical inactivity was $76.6 billion.¹

There are considerable published data to strongly support the benefits of PA and dietary changes as a means to decrease the morbidity and mortality of CVD and stroke in adults. Such data are presented and discussed in detail in the statements from the American Heart Association (AHA)⁷ and other sources. Notable statements and studies include, but are not limited to, the statement on exercise (AHA),⁸ the statement on PA intervention studies (AHA),⁹ the statement on diet and lifestyle recommendations (AHA),¹⁰ the 2005 Dietary Guidelines for Americans,¹¹ and the recommendation on PA and public health.¹² Despite the abundance of data supporting the benefits of lifestyle changes for CVD, it is striking that Americans are increasingly more challenged with the growing burdens of excess body weight, limited PA, and suboptimal dietary habits. These lifestyle problems are also associated with many chronic diseases other than CVD and stroke, including type 2 diabetes, osteoporosis, depression, and many cancers.

Cardiovascular risk factors can be combated and controlled by adherence to current lifestyle recommendations. One important example of success achieved in improving lifestyle habits is the achieved decline in prevalent tobacco use from 42.4% to 20.5% of American adults between 1965 and 2007.¹³ Although work remains in this regard, the success of tobacco cessation efforts provides a strong basis for optimism that a concerted evidence-based program of education, policy change, and individual interventions could successfully improve dietary and PA habits in the United States.

The purpose of this scientific statement is to provide evidence-based recommendations on implementing PA and dietary interventions among adult individuals, including adults of racial/ethnic minority and/or socioeconomically disadvantaged populations. The most efficacious and effective strategies are summarized, and guidelines are provided to translate these strategies into practice. Individual, provider, and environmental factors that may influence the design of the interventions, as well as implications for policy and for future research, also are briefly addressed.

Description of Data Search Strategies and Evidence Rating System

To identify articles concerned with diet and PA behavior change interventions in individuals, literature searches were performed in 5 databases; MEDLINE, CINAHL, Cardiosource Clinical Trials, Cochrane Library, and PsycINFO. Included studies were limited to adult humans (defined as ≥18 years of age); English language; randomized controlled or quasi-experimental designs or meta-analyses; focused on the effects of diet or PA interventions on weight, blood pressure (BP), PA level, aerobic resistance exercise, fitness, or consumption of calories, fruits, vegetables, fiber, total fat, saturated fat, cholesterol or salt; and published between January 1997 and May 2007. A few landmark studies that predate 1997 publication were included in our review. Despite extensive search efforts, all relevant studies may not have been identified; overall studies are representative and capture the state of the field.

Unpublished reports or reports published only in abstract form were not included. There was considerable variation in the direction and strength of findings within the studies reviewed; however, an effect of bias against publication of studies with null results cannot be ruled out. Studies were restricted to those conducted in the United States because societal and cultural factors can affect feasibility and success of particular intervention strategies; nonetheless, most of the findings may be generalizable to other developed nations. Feeding trials, observational studies of specific nutrients, and observational studies of aerobic capacity were excluded. Given the varying goals and outcomes of the different identified intervention studies, when possible we used a common measure of effect size (ES) to quantify and compare the success of each intervention.¹⁴ Recommendations follow the AHA and the American College of Cardiology methods of classifying the evidence (Table 1).

Findings

Details of studies of behavioral change interventions and related PA and dietary outcomes are presented in Tables 2 and 3. Because cognitive-behavioral strategies for promoting change are integrated across all reports, the studies in Tables 2 and 3 are organized according to the format of the intervention delivery. The majority of studies assessed changes in body weight and/or specific eating patterns (fruits/vegetables, dietary fat). Except for studies using standard behavioral interventions for weight loss, in which daily calorie and fat gram goals are provided, most studies did not target total energy intake. As shown in Tables 2 and 3, the ES for the between-group differences for the majority of studies was small, ranging from 0.00 to 0.33, except for the preliminary study of Carels et al,¹⁵ that used motivational interviewing to augment behavioral intervention and reported an ES of 0.84.

Cognitive-Behavioral Strategies for Promoting Behavior Change

Cognitive-behavioral strategies are an essential component of behavior change interventions. These strategies focus on changing how an individual thinks about themselves, their behaviors, and surrounding circumstances and how to modify their lifestyle. As illustrated in Tables 2 and 3, at least 2 or more strategies were incorporated in studies that yielded favorable outcomes.

Goal Setting

Several lines of evidence indicate that setting goals at the outset of the program is important to achieve the desired behavior change. Under most circumstances, setting specific goals leads to higher performance compared with no goals or vague goals.¹⁶ Compared with individuals who have vague or absent goals, individuals who target a specific behavior change are more likely to be successful.^17,18 Such goals may vary by degree of difficulty, specificity, and complexity; for example, making some dietary changes can be complex and requires several intended outcomes.¹⁹ The use of goals is more successful when the goals are specific in outcome, proximal in terms of attainment, and realistic in terms of the individual's capability.²⁰ Goals that focus on behavior (eg, increasing whole grain intake) rather than a physiological target (eg, improving low-density lipoprotein [LDL] cholesterol or glucose levels) are preferable because behaviors are under a person's more direct control and also observable by the individual, whereas several factors (eg, genetics) can influence physiological targets.^16,19,21,22

Setting appropriately ambitious goals is also important. Goals that are too difficult may not be attempted, whereas those viewed as too easy may not be taken seriously or provide a sense of satisfaction once achieved. Providing regular feedback on goal attainment is important to instill a sense of learning and mastery.¹⁶ Of the 74 trials described in Tables 2 and 3, 31 trials (42%) included goal-based diet and/or PA strategies.^23–53 Positive dietary or PA behavior changes were observed in all but 2^35,46 of the trials. Goals either set by participants^{43,44,46,48,54} or assigned by the healthcare provider can lead to desired outcomes (eg, weight loss).^26,38,53,55

Self-Monitoring

The purpose of self-monitoring is to increase one's awareness of physical cues and/or behaviors and to identify the barriers to changing a behavior. Self-monitoring facilitates recognition of progress made toward the identified goal (eg, minutes of PA or number of calories consumed per day), thus providing direct feedback. Self-based monitoring allows the individual to assess progress with the program on his/her terms, removing barriers such as travel or scheduling constraints associated with structured group programs. Self-monitoring interventions can be simple, such as pencil-and-paper logs of PA or dietary intake or charting of weight lost, steps taken, or distance walked.^{23,26,27,29,35,36,38,40,42,46,50–52,56–59} Self-monitoring strategies can be provided and then left to the discretion of the individual or applied in conjunction with external prompts incorporated into the behavior-change strategy. For example, such prompts can include scripted telephone messages or Internet e-mail reminders, specialized personal digital assistant (PDA) programs for monitoring dietary intake and PA, as well as both commercial and free-of-charge Internet-based programs.^35,36,57 Studies to date suggest that electronic self-monitoring systems can be effective for monitoring behavior changes. An advantage of electronic monitoring systems is their mobility, decreasing cost, and increasing availability; a potential limitation is the absence of human interaction.

Both observational data^60–64 and evidence from clinical trials^{26–28,30,36,38,50,52} demonstrate the importance of self-monitoring in achieving behavior change. A recent meta-analysis found that PA intervention studies using self-monitoring demonstrated larger effect sizes than studies without self-monitoring.⁶⁵ In a recent trial of weight loss, participants who self-monitored their food intake lost twice as much weight as those who did not self-monitor.⁶² Frequency of self-monitoring, as well as detail and proximity in time to the recorded behavior, can influence efficacy of self-monitoring.⁶² In a study testing interventions to promote weight loss, individuals in a combined therapy group who frequently recorded their weight achieved more than twice the weight loss than those who recorded their weight infrequently.²⁸ In the Women's Health Initiative Dietary Modification Trial, a randomized controlled trial in nearly 50 000 postmenopausal women, independent predictors of dietary change at 1 year included younger age, more education, having a more optimistic personality, attending more intervention sessions, and submitting more self-monitoring records.⁶⁴ Notably, at 3 years, the only predictors of continued dietary maintenance were attending more sessions and submitting more self-monitoring records.^63,64 Among the 25 trials with sizable minority representation in Table 3, only 6 included interventions that described self-monitoring.^{42,46,50–52,59} Five of these 6 trials that included self-monitoring^{42,46,50–52} led to positive lifestyle behavior changes, compared with 13 of the 19 trials that did not include self-monitoring. Thus, both in whites and minority populations, self-monitoring appears to be an effective complement to behavioral intervention strategies.

Frequent and Prolonged Contact

Compared with single-session interventions, the evidence suggests that programs that incorporate scheduled follow-up sessions as a core component are generally more effective.^{25,26,28,41,43,47,52,55,66–69} Frequent contact with individuals helps establish trust between the provider and individual, a component of care especially important among racial/ethnic minority groups.⁷⁰ Ongoing contacts can be delivered by various modes, including face-to-face, telephone, email or through the Internet.^{27,36,68,69,71} When combined with the use of group-based interventions, scheduled follow-up sessions provide several advantages, including social support from the peer group, an increased desire to succeed due to a sense of commitment to the group, and an opportunity to modify the program based on feedback from group members or the program leaders.

Across all behavioral domains, it is well-established that adherence to any new behavior will often decline as the intervention is reduced or withdrawn. Evidence suggests that as the frequency of contact decreases, achievement of initial behavior change also decreases.⁷² Further, any already achieved behavior change often diminishes over time as frequency of the follow-up decreases, and particularly so when the intervention ceases entirely.^41,59,68 Greater numbers and more prolonged time courses of follow-up sessions facilitate success across sequential stages of behavior change, such as new learning of diet and/or PA behavior change skills, practicing of these skills, problem solving and finding solutions to overcome relapse, integrating new diet and PA behavioral skills into one's daily routine, and learning skills to facilitate maintenance of new behaviors.⁷³ Among the trials reviewed (Tables 2 and 3), the majority of interventions that led to dietary or PA changes that lasted ≥12 months included follow-up contacts over at least 4 months.^{26,38,46,48,51,53,55,74–76}

There are few data on critical time points for follow-up. Expert opinion suggests that 6 months is a critical time to assess maintenance, but no data are available that compare this period with others between 3 and 12 months. Initial intervention and follow-up should be early and often, incorporating the expectation of self-monitoring and deliberate follow-up. In the absence of conclusive data, expert opinion suggests that follow-up beyond the initial visit could include visits at 6 weeks; then at 3, 6, 9, and 12 months; and then every 6 months thereafter if behavior change adherence is successful. Lack of adherence should prompt more frequent follow-up, whether in person, by telephone, or electronically. Further research is needed to confirm the feasibility and effectiveness of this suggested time frame versus other alternatives.

Feedback and Reinforcement

Healthcare provider feedback helps individuals learn new dietary or PA behavioral skills by providing an external measuring stick against which to assess their progress.⁷⁷ Feedback about behavior performance can illuminate consequences of diet and PA behavior for an individual, which may motivate individuals to continue a certain behavior or provide direction for adjusting behavior to reach a targeted goal.⁷⁸ When goal setting is combined with receipt of performance feedback, individuals can use information about their current level of performance to set realistic goals for improvement.⁷⁸ Evidence in Table 2 suggests that feedback is frequently included in successful behavior change interventions.^{24,27,29,30,32,33,36,44,46,52,55,57,69,71,79–81} Six of the 25 trials listed in Table 3 described provision of feedback as part of the intervention. Five of these studies resulted in positive lifestyle changes.^{44,46,52,55,81} Of the successful trials, all interventions included provision of feedback about the initial baseline screening results, and several included further feedback during follow-up assessments. Feedback based on initial screening can help individuals become aware of the need for behavior change, and feedback during follow-up provides updated information about ongoing behavior change efforts.

Self-Efficacy Enhancement

Self-efficacy, a component of social cognitive theory, describes an individual's perception regarding his/her abilities to carry out actions necessary to perform certain behaviors (eg, making changes in diet or lifestyle).²⁰ Perceived self-efficacy is a major determinant of performance independent of an individual's actual underlying skill.²⁰ The strength of perceived self-efficacy is particularly important, as individuals are more likely to both initiate a behavior and continue their efforts until success is achieved if their perceived self-efficacy is higher.²⁰ Thus enhancement of an individual's perceived self-efficacy can be incorporated into interventions to improve the likelihood of successful behavior change. Bandura's theory suggests 4 sources of self-efficacy that can be drawn on and incorporated into intervention strategies to enhance self-efficacy.⁸² The source with the greatest potential for increasing self-efficacy, mastery experiences, entails having a person successfully achieve a goal that is reasonable and proximal; for example, substituting fruit for a high-calorie dessert or being able to walk 1 mile. A second source, vicarious experience, consists of the individual witnessing someone who is similar in capability successfully perform the desired task; for example, observing patients exercise and improve their physical function in cardiac rehabilitation or watching a nonprofessional prepare a healthy meal. A third source, verbal persuasion, entails the provider persuading the person that he/she believes in the person's capability to perform the task. This is the weakest source for improving self-efficacy, but can be implemented via telephone or other electronic modes. The fourth source, physiological feedback, entails interpreting to the individual the meaning of different symptoms associated with behavior change. Examples include explaining that experiencing fewer symptoms with exertion is related to regular participation in a physical activity program or that feeling less fatigued or more comfortable is related to weight loss.²⁰ An extensive body of evidence indicates that self-efficacy influences behavior change across all the behavior domains related to CVD risk reduction.^83–92 Self-efficacy enhancements were incorporated into the interventions of several of the studies that yielded favorable outcomes.^{30,39,40,46,54,55,68,79,93}

Incentives

The efficacy of incentive programs to induce or support behavioral change has been most extensively studied at the workplace. The most commonly used incentives have been financial, such as health premium reductions or direct cash payments/bonuses for specific changes.⁹⁴ Few interventions described in this review included incentives,^34,57,76 and the return on investment from them has not been widely assessed. Novel but untested incentive strategies include rewards for employees frequently parking in the spaces located furthest away from the work site in the company parking lot or lowering the charge for use of on-site fitness facilities when frequency of use is higher.

Modeling

Modeling is a behavior change strategy that consists of having the person observe another individual perform behaviors (eg, engaging in PA or preparing healthy food) that are related to his/her goal. Among interventions described in Tables 2 and 3, several incorporated modeling, including use of in-person or video cooking demonstrations and personal PA training (having credible individuals demonstrate how to exercise and have the individual practice with them if possible).^{25,43,54,55,75,95,96} Another modeling approach is to have a person speak with someone who has been successful in making behavior changes (eg, maintained weight loss or a PA program). Exposure to models that are credible to participants can be an effective strategy to enhance skills for changing behavior and enhancing self-efficacy.⁸²

Problem Solving

Problem solving consists of 5 steps: identifying and defining the problem, brainstorming solutions, evaluating the pros and cons of potential solutions, implementing the solution plan, and evaluating its success.⁹⁷ Problem solving can be used to help an individual navigate barriers to behavior change (eg, negotiating support from the family when attempting dietary change). It is important to have the individual do the brainstorming when developing solutions and, when possible, to have the person practice the skill.⁹⁷Tables 2 and 3 describe several studies that included problem solving as a part of interventions that led to positive behavior change.^{31,32,39,41,43–45}

Relapse Prevention

Relapse prevention is an approach that makes a person aware that it is normal to deviate episodically from the goal behavior, such as missing some scheduled exercise sessions or giving up on the program due to lapses. Individuals are taught to recognize past situations that have placed them at risk for lapses from their dietary or PA behavior change program (eg, vacations or calendar holidays) and how to use behavioral and cognitive strategies for handling these situations.³⁰ Although few interventions reviewed specifically addressed relapse prevention as a strategy,^23,30,45 others may have indirectly addressed relapse prevention through the inclusion of social support,^{29,35,41,47,53,55,76,80} through problem solving to reduce barriers,^{31,32,39,41,44} or through a reinforcement program.⁹⁸

Motivational Interviewing

Motivational interviewing is a directive, individual-centered counseling style for eliciting behavior change with a central purpose of helping individuals to explore and resolve their ambivalence (ie, lack of readiness toward changing their behavior).⁹⁹ Briefly, the 7 key principles that characterize the nature of motivational interviewing include the following: (1) motivation to change is elicited from the individual, rather than imposed from without; (2) it is the person's task, not the counselor's, to articulate and resolve his or her ambivalence; (3) direct persuasion is not an effective method for resolving ambivalence^100,101; (4) the counseling style is generally a quiet and eliciting one; (5) the counselor is directive in helping the person to examine and resolve ambivalence; (6) readiness to change is not a person trait, but a fluctuating product of interpersonal interaction; and (7) the therapeutic relationship is more like a partnership than one in which there are expert/recipient roles.¹⁰⁰

Interventionist behaviors that are characteristic of motivational interviewing include seeking to understand the person's frame of reference, particularly via reflective listening, and expressing acceptance and affirmation; eliciting and selectively reinforcing the person's own self-motivational statements, expressions of problem recognition, concern, desire and intention to change, and ability to change; monitoring the person's degree of readiness to change; ensuring that resistance is not generated by jumping ahead of the individual; and affirming the person's freedom of choice and self-direction. Training and certification of the interventionist is necessary to achieve optimal results. There are several print and electronic resources to help clinicians wanting to learn more about motivational interviewing,¹⁰¹ including the following Web site: http://www.motivationalinterview.org/training/trainers.html. Referral to allied professionals trained in motivational interviewing is also an excellent option for individuals ambivalent about behavior change.

Evidence suggests that motivational interviewing can facilitate behavior change. A 2003 meta-analysis¹⁹ was conducted on controlled clinical trials investigating interventions that primarily implemented motivational interviewing principles. Four studies demonstrated a combined ES of 0.53 (95% CI, 0.32 to 0.74) for diet and exercise, thereby indicating moderate efficacy. Additional motivational interviewing studies reported increased fruit and vegetable consumption as part of general lifestyle change in whites and blacks,^32,102,103 firefighters,⁷¹ smokers,⁹³ and college students.¹⁰⁴ Other studies demonstrated that motivational interviewing increased PA among women and/or individuals with diabetes or obesity^15,40,105 and black individuals with hypertension.¹⁰⁶ An array of studies have reported improved body mass index or weight loss using motivational interviewing in workers in Oregon,¹⁰⁷ other occupational settings,¹⁰⁵ black individuals with hypertension,¹⁰⁶ and white females.¹⁵ Overall, there is general consensus that motivational interviewing offers an evidence-based approach for enhancing adherence to behavioral interventions, including dietary and PA change.

Intervention Processes or Delivery Strategies

Targeting Single Behaviors Versus Multiple Behaviors

Evidence described in Tables 2 and 3 shows that interventions may focus on changing only PA,^{34,46,69,108,109} only dietary behaviors,^{17,24,30,32,33,39,47,48,54,68,74–76,80,81,96,110} or both.^{26–29,35,36,38,43,44,50,51,53,55,57,66,67,111–113} Studies that focus on multiple behaviors have generally applied the same type of intervention strategy (eg, provision of education materials, counseling sessions, follow-up monitoring) to change each specific behavior. Results of these studies have been variable. Most reported positive results (ie, the desired change in both PA and dietary behaviors). However, studies have not consistently resulted in improvements in related metabolic/vascular biomarkers (eg, serum lipids, blood pressure). The results of a meta-analysis of studies testing interventions to increase PA among older adults indicated that interventions targeting only PA resulted in higher ES than studies designed to change multiple health behaviors.⁶⁵

There is limited knowledge about the relative benefits of simultaneous versus sequential delivery of multiple PA and dietary behavior change interventions in adults. In a randomized trial of 289 blacks with hypertension, participants were randomized to 1 of 3 groups: (1) an in-clinic counseling session every 6 months on smoking, reduced dietary salt intake, and PA, supplemented by use of motivational interviewing strategies by telephone for 18 months; (2) a similar protocol that introduced 1 behavior every 6 months; or (3) a 1-time referral to existing group classes.¹⁰⁶ When examining individual target behaviors at 6 months, 29.6% in the simultaneous, 16.5% in the sequential, and 13.4% in the usual care arms had reached the urine sodium goal (P=0.01 for the simultaneous versus the usual care group and P<0.05 for the simultaneous versus the sequential group). At 18 months, 20.3% in the simultaneous, 16.9% in the sequential, and 10.1% in the usual care arms were negative for urinary cotinine (P=0.06 for the simultaneous group versus the usual care group and P=0.08 for the overall trend in smoking cessation), whereas 6.5% in the simultaneous arm, 5.2% in the sequential arm, and 6.5% in the usual care arm were adherent to ≥2 target behaviors (all statistical contrasts resulted in P>0.05). In contrast, findings from another trial among 315 female smokers supported a sequential over simultaneous approach to multiple behavior changes, including diet, exercise, and smoking cessation.¹¹⁴

It is worth noting that additional studies published later than our time window or performed outside the United States have also shown mixed results for superiority of sequential versus simultaneous intervention strategies.^115,116 In 1 trial, at 6 months, the simultaneous strategy was superior for a fat intake intervention and for a subgroup of participants who did not meet physical activity recommendations at baseline.¹¹⁵ However, the sequential intervention resulted in better maintenance of intervention effects at 2 years.¹¹⁷ Thus, the relative merits of simultaneous versus sequential intervention are unresolved, and more studies comparing these intervention modes are needed.

Print- or Media-Only Delivery Strategies

Media messages, printed materials, and other nonindividualized strategies may be used to provide information to individuals to encourage PA and dietary change. In a study involving individuals with mild hypertension, the use of nonindividualized educational mailers did not significantly decrease BP.¹¹⁸ Overall, self-help approaches that provide nonindividualized brochures and other behavioral learning tools without any additional personal counseling appear to produce little benefit.⁵⁵

In contrast, in a study comparing the efficacy of nonindividualized self-help manuals versus motivationally matched reports and manuals to promote PA adoption, both groups showed significant improvement in PA at 6 months, but the increase was 50% greater among participants receiving motivationally matched materials.⁷⁹ The mode of delivery may also influence efficacy. In a study comparing the effects of motivationally matched print materials versus motivationally matched telephone counseling, both groups had significantly increased PA at 6 months, but participants receiving the print materials were more likely to maintain PA change at 12 months.⁶⁹ Thus, whereas further research on optimal modes of delivery is needed, the evidence suggests that individualized print or media material are more effective than nonindividualized ones.

Group, Individual, Technology, and Multicomponent-Based Delivery Strategies

Four general approaches can characterize interventions to modify dietary intake and increase PA, including (1) group-based interventions, (2) individual-based interventions, (3) computer/technology-based (interactive session, personal or automated telephone calls) interventions, and (4) multicomponent interventions.

Group-Based Interventions

Group-based interventions are characterized by opportunities for social interaction, support from others who are experiencing similar challenges in modifying their lifestyle, role modeling, and positive observational learning.²⁹ Group-based approaches are commonly used in randomized clinical trials employing standard behavioral interventions for weight loss,^{24,25,28,29,66,72,109} as well as in other trials using diet and PA changes to target CVD risk factors such as BP or blood cholesterol.^{23,26,27,56,66,67,113} In a meta-analysis of studies that tested interventions to increase PA among older adults, group-based intervention delivery resulted in larger ES than individual-based interventions.⁶⁵

Group-based interventions have been successful in both white²⁸ and minority populations.⁷⁶ The majority of studies with minority populations (18/25) included group-based intervention strategies.^{42,43,46–48,51–55,59,74–76,96,110,112} Minority populations ranged from being 100% black,^{42,43,51,55,75,76,102,103,119} 73% to 100% Hispanic,^{44,46,52,53,110} to smaller subsamples of blacks and/or Hispanics.^{26,45,47,48,50,54,74,93,96,112,113}

Typically, group interventions are administered in a small, closed group format (eg, 7 to 10 members). Groups initially meet as often as weekly, with meeting frequency often decreasing over time.^28,43 Sessions may be led by a lay person or a professional.^{43,46,56,58,76,113} Successful group-based interventions incorporate didactic education, counseling strategies, and multiple behavior change strategies such as goal setting and self-monitoring.^26,38 Some group-based programs have included skill-building sessions such as food label reading; grocery shopping; methods for healthy cooking; practice using pedometers, exercise bands, or other exercise equipment; and walking groups.^24,68 Of the trials in Table 3 with a group-based intervention delivery, approximately one third (n=9) incorporated the use of skill-building strategies.^{43,46,47,54,55,59,74,76,112} Among these, all but 1 study⁴⁶ demonstrated at least within-group positive changes in dietary or PA behaviors or improved CVD risk factors.

In group-based weight loss interventions, the greatest weight loss usually occurs within the first 6 months of the study.^15,30,120 Regardless of type of diet or activity, investigators typically report that many individuals find it challenging to maintain the reduced caloric intake and/or PA plan, and weight is often regained by many individuals as early as 4 to 6 months into the program. A major challenge in weight management is identifying strategies to assist individuals in maintaining long-term weight loss.^24,121 To achieve this, investigators have tried supplementing the group-based approach by recruiting participants with friends and enhancing social support,²⁹ providing home exercise equipment,¹⁰⁹ using aerobic or strength-training exercises,⁷² providing improved access to counselors through the Internet,^36,57,122 and using a stepped-care approach and motivational interviewing for those who did not meet their weight loss goals.¹⁵ The studies found improvements in all groups, with small between-group differences in energy and fat consumption or PA changes, suggesting that supplementary strategies to most basic group-based approaches do not have a major effect on efficacy; however, most approaches that include the basic elements of standard behavioral treatment will have a positive effect on eating and PA habits and will result in weight loss, at least for the short term.

Commercial programs that use the group approach and a self-monitoring system to guide food restrictions (eg, Weight Watchers) appear to be more effective than self-help approaches. For example, in a trial among 212 adults,^123,124 greater weight reductions were observed at both 1 and 2 years in the commercial group compared with the self-help group, with accompanying improvements in BP, blood lipids, insulin, and glucose levels. Although such commercial programs have many similarities to the empirically tested noncommercial ones described above, having access to continued group support and ongoing contact for 2 years may be the salient features of these programs compared with a self-help approach. However, due to their cost, commercial programs may be less available to socioeconomically disadvantaged populations.

Individual-Focused Interventions

Individual-focused interventions allow tailoring or personalization of healthcare recommendations to the learner's particular health concerns and life context. Individualized counseling has been effectively provided by health educators and/or counselors,^31,32,125 physicians,⁹⁵ and/or other healthcare professionals.³⁰ A meta-analysis of randomized clinical trials testing interventions to promote PA among older adults found that individualized interventions consisting of a health risk appraisal, activity counseling, and/or cognitive-behavioral strategies resulted in increased PA levels for at least short term (<1 year), compared with a control group.¹²⁶

A wide range of individual-based strategies have been tested, including in-person, telephone, electronic, and combined approaches. For example, among the studies reviewed, individual-only approaches included 6 biweekly telephone sessions,³⁰ 3 monthly telephone sessions,³¹ one 8-minute physician-provided counseling session during a clinic visit,⁹⁵ three 30- to 45-minute face-to-face counseling sessions followed by 12 counseling telephone calls,¹²⁵ and 2 face-to-face 45-minute counseling sessions followed by two 5- to 10-minute telephone calls 3 and 6 weeks after the sessions.³²

Combined individual-based approaches appear to be successful in creating behavior change. For example, the use of personal goal setting and self-monitoring via individual telephone counseling improved adherence to a cholesterol-lowering diet and reduced serum cholesterol compared with usual care.³⁰ In another trial, supplementing clinician advice with telephone counseling by a health educator was more effective in improving levels of PA than clinician advice alone.¹²⁵ In a study comparing physician-delivered nutrition counseling alone versus physician counseling combined with in-office prompts to usual care,⁹⁵ only the combined program decreased participants' saturated fat intake, weight, and LDL cholesterol. The average counseling time was 8.2 minutes, 5.5 minutes more than in the control group.⁹⁵ No studies were identified that examined the effects of in-office prompts only, in-office reminders only, or in-office dietary and/or PA assessment tools only on diet and/or PA behavior change; more research is needed in these areas.

Three studies that addressed individual-based CVD risk reduction in the practice setting were published earlier than our time window of published articles or were performed outside the United States but warrant mentioning here.^127–129 In 1 study, nurses initiated interventions for smoking cessation, exercise, and diet and drug therapies for hyperlipidemia among hospitalized individuals who had suffered an acute myocardial infarction.¹²⁷ They followed the study participants after hospital discharge by telephone and mail contact. Compared with usual care, the intervention group reported higher functional capacity at 6 months and higher smoking cessation rates and lower LDL cholesterol at 12 months.¹²⁷ A second study delivered a 4-year intervention to assist individuals with coronary artery disease in meeting several CVD risk reduction goals through improving diet and PA, smoking cessation, and drug therapy.¹²⁸ After an individualized session with a nurse at baseline, individuals were followed-up by mail and telephone contact and seen every 3 months in the clinic. Compared with usual care, the intervention group had less progression of coronary atherosclerosis and decreased hospitalizations for cardiac events.¹²⁸ This is one of the few trials of sufficient size and follow-up duration to demonstrate that PA and dietary changes lead to reductions in clinical end points. A third trial, EUROACTION, investigated the efficacy of a nurse-coordinated multidisciplinary, family-based (rather than individual-based) preventive cardiology program conducted in 8 European countries for both primary and secondary prevention.¹²⁹ Compared with usual care, more individuals and their partners in the intervention group achieved recommended targets for PA and for fruit, vegetable, saturated fat, and oily fish consumption. Central obesity was also reduced. These findings indicate that a nurse-led multidisciplinary team approach, coupled with support and involvement of an individual's partner and family, can yield significant lifestyle improvements and cardiovascular risk factor reductions.

Because the studies described here utilized interventions that were delivered at the individual level, cognitive-behavioral intervention strategies may also have been incorporated and improved efficacy. For example, some studies incorporated motivational interviewing strategies^{32,93,103,125}; some used goal setting, feedback, and/or self-efficacy enhancement^30,79; and others used readiness to change^{31,45,69,104,125,130} or problem-solving^31,32,44 strategies. Overall, individual-based interventions have been shown to be successful, at least for the short term (up to 1 year). In studies with minority samples (Table 3), individual intervention approaches to promoting change seem to result in smaller or fewer changes in total diet or PA compared with group-only⁵⁵ or combined individual- and group-based approaches.^26,38,47,51 Research has yet to establish when and for whom individual-only approaches are most appropriate.

Further investigation should better quantify the processes and comparative effects of specific individual interventions. Key questions include whether the type of provider (eg, nurse, physician) influences efficacy; what specific combination of cognitive, behavioral, and informational strategy is most effective; and what are optimal strategies for including family members.

Computer/Technology-Based Interventions

With the growth of computer technology and the Internet, health interventions are increasingly delivered online or with the use of technology. Several advantages of Internet-based interventions have been cited,¹³¹ including ability to reach many people with a single posting; easy storage of large amounts of information; ease of updating information; ability to provide personalized feedback; cost effectiveness and convenience for users; ability to reach people suffering from isolation or conditions that cause them to feel embarrassed or stigmatized; timeliness of access; user control of the intervention; supplier control of the intervention; and ease of adapting information for specific populations.^{36,57,108,122,132}

Several studies have employed the use of the Internet or computer-based programs to deliver education and counseling interventions for weight loss and dietary change.^{17,33–36,57,108,122,132} (Table 2). Three studies demonstrated that the combination of an Internet program (eg, weekly reporting and graphs of weight, recipes, and weight loss tips) plus E-counseling (eg, automated praise or feedback) resulted in greater weight loss than use of the Internet program alone.^36,57,122 Another study found that Internet-only counseling was as effective for weight loss at 6 or 12 months as Internet-only counseling plus monthly in-person counseling.³⁵ A strategy of interactive, computer-controlled telephone systems for educating participants about a healthy diet resulted in some improvements in fruit, fiber, and saturated fat intake.¹⁷ A supermarket kiosk program providing onsite nutrition information also resulted in improvements in fat, fiber, fruit, and vegetable purchases and intake.³³

A few US trials have evaluated the efficacy of Internet or computer-delivered interventions to increase PA.^34,108,132 In 1 small trial (N=65), use of a PA Web site and 12 weekly E-mail tip sheets resulted in increased total minutes of walking, but not time spent in moderate PA at 1 and 3 months, compared with a control group.³⁴ In a larger and longer randomized clinical trial, investigators compared a motivationally tailored Internet intervention to motivationally tailored print material and to publicly available PA Internet sites; at 6 and 12 months, there were no significant differences in minutes of PA among the 3 groups.¹⁰⁸

Few Internet studies have been conducted among minority and/or socioeconomically disadvantaged populations. Investigators have reported that low-literacy individuals may have difficulty accessing information through the Internet because of suboptimal searching strategies (eg, use of nonspecific search terms), unwillingness to click on links, accessing Web sites written at or above the 10th grade reading level, and perceived higher quantity and complexity of the information.^133,134 An understanding of the target population appears essential to optimize delivery of Internet-based diet and PA behavior change interventions.

Overall, the results of these trials are mixed, but at least in some scenarios, the use of Web-based and computerized materials appears to improve weight loss and certain dietary behaviors; fewer studies have evaluated PA. Combinations of technology-based approaches may be more effective than single interventions; for example, the addition of E-counseling appeared to improve efficacy of Internet-based programs for weight loss.³⁵ The use of the Internet can allow healthcare providers to reach a greater number of sedentary adults in a cost-effective manner, but several important questions remain unanswered, including effectiveness in low-income and minority samples, utility for increasing PA, long-term sustainability, optimal components of Internet interventions (eg, number of log-ins, E-mails, online chats) and relative efficacy versus traditional printed material.

Multicomponent Intervention Delivery Strategies

In contrast to single strategies, most trials have evaluated multicomponent interventions (Tables 2 and 3). Multicomponent programs include combinations of technology/media; group or individual-based delivery strategies such as interactive computer-based programs plus telephone follow-up and community resource enhancement⁸⁰; computerized assessment and feedback plus videotapes, telephone follow-up, or individual counseling^32,39; physician advice plus motivational videotapes, telephone calls, and interactive mail¹³⁵; group sessions plus individual motivational interviewing^15,40; or individual plus group sessions.^38,41,58,111 In most multicomponent studies, various behavioral strategies were also included, including goal setting, self-monitoring, feedback,^{38–41,46,49–53,55,58,59,80,81,111} social support,^49,76 problem solving,^39,41 or motivational interviewing.^15,40,102

Among nonminority populations (Table 2), all 10 multicomponent intervention trials reviewed demonstrated positive dietary and/or PA outcomes. Among the 16 multicomponent intervention trials involving minority populations (Table 3), most ^{47–53,55,74–76,81,102,112} demonstrated some positive changes in either dietary and/or PA behavior. The 2 trials of multicomponent interventions that did not lead to dietary or PA changes^46,59 may have been limited by insufficient duration or lack of effective combination of behavior change strategies. The optimal combination of behavior change strategies in multicomponent interventions has yet to be determined.

As part of a personalized, medical office-based intervention focused on dietary self-management for individuals with type 1 or 2 diabetes, a computerized assessment of potential dietary barriers was used to immediately generate 2 printed feedback forms that were provided in combination with personalized counseling and other self-help materials.³⁹ One year later, significant decreases were observed in total fat intake and serum cholesterol levels, but not hemoglobin A1c levels. One of the most successful multicomponent studies has been the Diabetes Prevention Program (DPP).³⁸ The DPP used individual counseling in the intensive lifestyle intervention arm of the trial, with goals of 7% weight loss and 150 minutes per week of PA.³⁸ Compared with a control group that received some group education, participants assigned to the lifestyle intervention had greater dietary changes, increased levels of leisure-time PA, and greater weight loss. Incidence of diabetes and metabolic syndrome were reduced by 58% and 41% in the lifestyle and control groups, respectively. Notably, the effects of the intensive lifestyle treatment did not differ significantly by sex, race, or ethnicity. The Look Ahead Trial,¹¹¹ an ongoing, multicenter randomized clinical trial of participants with type 2 diabetes mellitus, combined individual and group sessions. At 1 year, the trial reported significantly greater weight loss, improved fitness, and lower mean hemoglobin A1c in the combined group compared with those who received diabetes support and education through a limited number of group-only meetings.

Special Considerations for Interventions With Minority and Socioeconomically Disadvantaged Populations

In the United States, numerous racial and ethnic groups exist with diverse cultural norms, values, attitudes, beliefs, and lifestyle patterns. Interventions designed to change dietary and/or PA behavior in 1 population group may be less effective in another group, especially when the population is educationally or economically disadvantaged or differs in cultural health beliefs or practices from the population in which the intervention was initially tested. Optimally, methods to design or adapt interventions should be directly assessed in diverse populations and settings. Relatively fewer studies (n=25) within the specified time period for this review (1997 to 2007) evaluated samples other than white middle- or upper middle-class Americans. The most commonly studied minorities were blacks and Hispanics. Studies in Hispanic populations often did not adequately address linguistic competency. Although intervention studies have been conducted that included Asian American and Native American populations, in most, numbers were insufficient to conduct ethnic-specific subgroup analyses. Table 3 displays the 25 studies that included ethnic minorities or low-income participants that were reviewed and that provide the basis for additional discussion about implementing dietary and PA change interventions in these population subgroups. It is important to recognize that additional diversity occurs within racial/ethnic groups, so that intervention designs should consider the potentially diverse values, beliefs, and socioeconomic characteristics within each group.

Setting in Which Healthcare Is Delivered

For interventions in minority or socially and/or economically disadvantaged populations, an important consideration is identifying a setting to minimize the barriers to access the intervention. Once access is established, Table 3 indicates that interventions conducted in work sites, clinics, communities, and churches can lead to improved dietary intake and PA levels among blacks and/or Hispanics.

Peer/Lay Led Versus Professionally Led

Research suggests that people are more likely to hear and personalize messages, and thus to change their attitudes and behaviors, if they believe the messenger is similar to them and faces the same concerns and pressures.¹³⁶ It is therefore important to consider when a person may be more likely to believe a lay health advisor versus health professional thought to be an authority figure. Lay health advisors, peer educators, or community health workers are trusted community members and usually live in the same communities, speak the same language, have similar values and beliefs, and understand the cultural context of the minority target population.^137,138 Lay leaders can improve the quantity of messages about healthy behavior and tailor messages to the unique needs and culture of the target population.⁷⁴ The homophily for ethnicity (ie, the tendency of individuals to associate and bond with similar others) is important and may affect whether lay advisors or healthcare professionals are more effective.

Of the 25 trials reviewed (Table 3), 3 tested lay-led group or individual-level interventions,^43,48,74 and 4 tested interventions that combined professional and lay educators.^52,53,55,76 All these trials generally showed some positive changes related to diet and or weight. The trials using both professionals and lay leaders also further led to positive outcomes in diet,^55,76 blood cholesterol and BP,^53,55 PA,⁵³ and hemoglobin A1c at follow-up.⁵² It is also important to note that several studies demonstrated that professional-only led interventions can also lead to improved diet and PA changes in minorities.^{42,45–47,93,103} Given the well-documented history of discrimination toward minorities in healthcare settings, and a greater awareness of historical discrimination against blacks,^70,139–141 expert opinion agrees that provider capacity for trust building, communication skills, and cultural sensitivity are important ingredients of professional-led interventions.

Cultural Sensitivity

Cultural sensitivity in health promotion interventions refers to designing and delivering interventions that are relevant and acceptable within the cultural framework of the target population.¹⁴² Development of culturally sensitive interventions depends on knowledge of the history, values, belief systems, and behaviors of the members of the target minority group. The ability to overcome language barriers faced by non–English-speaking immigrants is also necessary.¹⁴³ Of the 25 trials reviewed (Table 3), 18 designed culturally sensitive interventions and had mixed results.^{43–47,52,55,59,74–76,81,93,96,102,103,110,144} In comparison, the results of the trials not including culturally sensitive interventions^{42,48,49,51,53,54,112} demonstrated within- and/or between-group differences in diet, PA, or related metabolic/vascular biomarkers. Thus cultural sensitivity alone is not sufficient and needs to be combined with essential behavior change strategies to produce positive outcomes.

Literacy Level Sensitivity

Without adequate literacy skills, individuals cannot read health-related materials. When working with persons of lower educational levels, literacy assessment and modification of methods for providing health information are useful. Effective strategies include use of audiovisual and interactive multimedia rather than print media; use of simple messages with short sentences, 1- or 2-syllable words, and large print with lots of space; and nonreliance on the Internet for provision of information.^{54,110,145,146} Seven of the 25 studies described in Table 3 used interventions sensitive to literacy levels^{44,45,47,52,54,74,81}; 6 of these^{44,45,47,52,74,81} resulted in some positive outcomes. The trial with null outcomes⁵⁴ lacked other intervention components such as specific behavioral goals, self-monitoring, or feedback that may have lessened the efficacy of the intervention.

Barriers to Behavior Change

Reported barriers to healthy eating among the disadvantaged and/or minority groups include poor dental health, lack of access to quality produce at affordable prices, inability to find ethnically preferred fruits and vegetables in local markets, transportation problems, family customs/habits, social and cultural symbolism of certain foods, and low price and easy access to snack foods.^147–152 Neighborhoods in which lower socioeconomic status individuals often live may not be conducive to exercise due to high traffic, poor lighting, waste sites, infrastructure deterioration, high crime rates,^151,153 and lack of availability of facilities that enable and promote PA.^154,155 Thus assessment of barriers to behavior change should be part of interventions targeting these population groups.

Acculturation

Evidence supports that acculturation of immigrants to the United States negatively influences healthy dietary patterns.^156,157 For example, highly acculturated Hispanics ate fewer servings of fruits and vegetables per day compared with those not highly acculturated, suggesting that healthcare providers need to encourage immigrants to retain traditional healthful eating patterns. Thus assessment of acculturation may be helpful in designing and implementing interventions to improve dietary habits in immigrant groups.

Fostering Initiation and Maintenance of Behavior Change

Several factors influence the design of optimal interventions and may influence a person's ability to adopt and maintain new lifestyle behaviors. First, various psychological factors enable individuals to adopt as well as sustain new behaviors long term. For initiating a behavior, persons' consideration of the anticipated benefits must compare favorably to their current situation, and they need to hold favorable expectancies regarding future outcomes.^4,158 The decision to maintain a behavior is dependent, at least in part, on whether the achieved outcomes associated with the new behavior pattern are sufficiently desirable to sustain the behavior (ie, on the individual's perceived satisfaction with the outcomes of that behavior change). Most individuals have clear expectations about what a new lifestyle will provide; if their experiences do not meet those expectations, they will be dissatisfied and less motivated to maintain it, particularly in environments that are frequently not supportive of healthy choices.

Other factors that may influence adoption and maintenance of new PA or dietary behavior include:

• Age—Evidence suggests that older age per se does not significantly reduce the response to PA or dietary interventions. Older age may be associated with more healthful dietary patterns and better adherence, such as higher consumption of fruits.^159–163 In the DPP trial, the greatest risk reduction in response to the lifestyle intervention was seen in the oldest age group, suggesting better adherence and/or efficacy in this group. However, although older adults on average may have better adherence, some may have barriers to overcome to achieve this adherence. For example, some older adults may be at particular risk for poor dietary habits, especially if they live alone and/or have low incomes. Although younger adults are more likely to cite time as the main constraint to exercise,¹⁶⁴ older adults most frequently cite poor health, including pain, reduced mobility, and low endurance.¹⁶⁵

• Sex—Lower PA levels in women than men are generally reported.^166–168 Women, however, are reported to have better eating habits than men.^169–174

• Better health status has been associated with greater levels of PA.^175–177

• Obesity, higher body mass index, and smoking are associated with lower PA levels.^{175,177–179}

• Presence of comorbid conditions and depression negatively impact adherence to most lifestyle change regimens.^180–183

• Deficits in cognitive processing and memory can reduce adherence, particularly for complex regimens.^184,185

• Individual differences in perception and assessment of costs and benefits of behavior change, when different from provider expectations, may alter responsiveness to interventions.¹⁸⁶

• Conscientiousness and self-efficacy each have been reported to favorably impact adherence.¹⁸⁷

• Somatic factors related to side effects negatively impact adherence to most regimens.^180,181,188

• Availability of social support positively influences PA and healthy food choices.^29,189–192

• It is important to consider the above-listed factors as well as the knowledge levels and skills of the individual before implementing therapeutic lifestyle changes.

Recommendations

Table 4 provides evidence-based and expert opinion recommendations on designing and implementing PA and dietary interventions in adults. Recommendations are organized to aid clinicians: to use cognitive-behavioral strategies to assist adults to adopt and maintain healthy dietary and PA targets; to make decisions about behavior change intervention processes and delivery strategies; and to modify interventions for addressing cultural and social context variables that influence behavioral change. The level of evidence base for these different recommendations varies; a few are supported more strongly by expert opinion or case study rather than direct research findings. The strength and types of evidence used to derive each recommendation are indicated in Table 4.

Subsequent to May 2007, when the literature review was completed for this publication, results from a few landmark studies conducted in large study populations were published. These include the POUNDS Lost Study (N=811), which compared 4 diets for weight loss, and the 1-year weight loss data from the Look AHEAD Study (N=5145).^193–195 In each case, weight loss itself, however it was achieved, was associated with reduced CVD risk. In addition to a specified dietary intervention, these studies included behavioral counseling strategies that are described in detail in this article, which were implemented to promote behavior modification for weight loss and to complement the dietary and/or physical activity components of the intervention. Consistent with the recommendations made in Table 4 in the present article, weight loss success was attributed to the best adherence to behavior and dietary recommendations.^193–195 The results of these studies add further and consistent support for the recommendations made herein that include state of the art behavior change strategies to counsel individuals in order to promote weight loss as needed along with the dietary and physical activity changes to maximize reduction in CVD risk.

Implications for Healthcare Policy and for Other Policy

Changes in healthcare policies are needed to make it more feasible to follow the recommendations made in this statement. Providers face numerous barriers to assessment and counseling for therapeutic lifestyle change. Although a major provider barrier to adherence in the acute inpatient setting is a focus on the acuity of the presenting problem, the major provider barrier in the outpatient ambulatory setting is limited resources for counseling and sustained follow-up support.¹⁹⁶ Across all settings are the persistent and ever-growing issues of provider time restraints, lack of financial incentives or reimbursement for health promotion, skepticism regarding whether health promotion counseling will result in behavior change, insufficient information about the most effective counseling strategies, lack of skills necessary to provide positive individualized counseling using both verbal and nonverbal communication skills, and doubts about the likelihood of lifestyle changes resulting in the desired outcome.^197–199 Physicians and nurses often cite their own lack of confidence in a person's ability to use preventive strategies for long-term behavior change.^200–205

Healthcare delivery systems need to address policy to ensure an environment that supports preventive interventions.²⁰⁶ Examples of healthcare system policies needed to strengthen the provider's ability to promote PA and dietary lifestyle changes include: use of tracking, reporting, and feedback systems; assessment of practice goals and benchmarks; availability of toolkits containing assessment tools and diet and PA behavior change guidelines; education and training for providers, including cultural sensitivity training; provision of incentives that are tied to desired individual and provider outcomes; and development of mechanisms for obtaining data on diet and PA behavior before a provider visit. It is encouraging that the American College of Cardiology Foundation/AHA's 2009 performance measures for primary prevention of CVD in adults include lifestyle counseling.²⁰⁷ Performance measures for diet and PA intervention are critical to improve the value placed on these interventions by the reimbursement system.²⁰⁷

It is important to note that other factors not included in this review will affect whether our evidence-informed recommendations are feasible for implementation, will result in improved levels of cardiovascular risk factors, and will prevent clinical events. Policies that foster individual healthy lifestyle choices are needed. For example, insurance premiums could be lowered for those who participate in programs around healthy diet and PA behaviors. Legislative initiatives geared toward providing more complete and accessible information to the general public or limiting the use of certain food components in the food supply, coupled with guidance on how to use that information or implement the policy, has been shown to positively influence food choices and foods available. For example, mandatory calorie labeling at point of purchase enacted by the New York City Health Department has provided expanded information for individuals about their food choices.²⁰⁸ This legislatively mandated regulation has been coupled with large-scale education initiatives on how to use the information. An environmental legislative initiative also championed by New York City is the staged phase-out of partially hydrogenated fat by food purveyors.^209,210 Extensive support systems to the food producers to provide advice and assistance in how to make the change and where to obtain the alternate fats were key ingredients in the success of the program. Many other cities have adopted or have legislative efforts underway to mandate law that food purveyors phase out industrially produced trans fats. As of October 2009, California passed legislation to limit trans fats, and numerous other states have similar legislation under review (http://www.ncsl.org/default.aspx?tabid=14362).These types of approaches, if enacted in a collaborative fashion, can serve to shape an environment where optimal lifestyle choices are available and in some cases are the “default” options.

Community environments have been extensively investigated in relation to PA and diet.^9,211–216 Special efforts by community groups, businesses, and government to increase the availability of healthier food and PA choices will complement provider interventions to implement lifestyle changes. Policies for providing wide and safe routes for walking and biking in communities and along state and federal roads, maintaining public parks, reducing exposure to unhealthy fast food or to high-calorie/low-nutrient foods, menu labeling, and increasing access and availability to healthy foods appear crucial.

Workplace policies designed to engage employees to achieve optimal health, as well as provide opportunities for organized PA (eg, lunch hour walking programs, instructor-led group exercise) and more healthy eating options (eg, cafeterias, vending machines, healthy taste clubs) will complement provider efforts to implement lifestyle change. A synthesis of older studies indicated that a point-of-decision prompt to use the stairs instead of an elevator or escalator resulted in a median increase in stair climbing of 53.9%.¹⁸⁹ More recent studies have confirmed the positive effects of signage on stair usage in public buildings¹⁹⁰ and have shown that experimentally reducing the availability of escalators and modeling more active behaviors increase stair use.^217,218 In summary, healthcare system policy and other policy changes are needed to increase the effectiveness of our evidence-based recommendations to improve diet and PA behaviors.

Where Do We Go From Here? Implications for Future Research

Evidence suggests that cognitive-behavioral strategies are an essential component of interventions targeting dietary and PA behavior change. We know that individual, group, and multicomponent intervention delivery strategies are effective; however, we need comparative studies to demonstrate the relative strengths and weaknesses of implementing multicomponent strategies versus any single strategy. We also know that computer/Internet-based delivery strategies are effective for selected populations. However, the ability for newer technologies such as text messaging and social networking tools such as Health Vault, Twitter, and Facebook to facilitate dietary and PA change needs to be determined.

There are many other gaps in our current knowledge about promoting lifestyle change. Comparative studies evaluating the effectiveness and intensity of diverse interventions are needed to identify the interventions most likely to succeed in both initiation and maintenance of diet and PA lifestyle changes. Optimal follow-up strategies to maximize the duration of change needs to be addressed in future studies. We do not know the specific design features that determine which interventions are most effective for whom (eg, young-old, male-female, high-low socioeconomic status) and at what cost. More knowledge about treatment receptivity or efficacy across different sex, racial, ethnic, or socioeconomic groups is needed. Many of the studies reviewed included samples of predominantly well-educated whites, and several studies targeted blacks and Hispanics; more studies that target other racial and ethnic minorities such as Asians, Native Americans, or Arab Americans are needed because these groups are also at risk for CVD.²¹⁹ The majority of studies reviewed (≈57%) contained samples that were predominantly (≥70%) female. Although this representation of women is an improvement from that reported in an earlier review of 49 studies of compliance to pharmacological, exercise, nutritional, and smoking cessation therapies (85% male),¹⁸⁷ we still do not know the extent to which lifestyle change interventions should be tailored to sex. The absence of males in most of the weight loss trials may reflect reluctance of some investigators to mix sexes,^29,36,57,109 as well as lower numbers of males who seek weight loss treatment or respond to recruitment efforts for studies that include men.^24,62 More research is needed on weight loss interventions in men, among whom the obesity epidemic is similarly rampant.²²⁰

Although the studies reviewed examined the influence of behavior change on surrogate end points such as lipid or BP changes, few examined the influence of behavior change on CVD events, mortality, hospitalizations, or quality of life.^221,222 More studies with longer-term follow-up of individuals who are able to maintain behavior change are needed to allow evaluation of these clinical end points.

The next generation of studies should also investigate how individual interventions interact with the multiple levels of environmental influences on PA and dietary behavior change. Both increased scope and detail of investigation are needed to understand the combined effects of individual behavior, healthcare system, and sociocultural and environmental factors. Health-promoting community design,²²³ active-living communities,²²⁴ and providing a healthier food environment should be incorporated into future studies to investigate multiple levels of environmental influences on health behavior.

Lifestyle interventions often target constructs based on social cognitive theory (eg, self-efficacy, self-regulation [self-monitoring, goal-setting, feedback], social support, observational learning) or the trans-theoretical model of change (eg, stages of motivational readiness). More evidence is needed to determine whether one or the other theoretical approach may be better in specific circumstances.

Lack of reimbursement for therapies targeting dietary and PA lifestyle change is a barrier for healthcare providers. In order to establish a case for reimbursement, we need to better understand the expected costs and cost-effectiveness of such interventions in the community. Future research must more carefully examine effectiveness of behavior change strategies in routine clinical practice, as opposed to efficacy trials that examine interventions under more structured ideal conditions. The efficacy of different behavior change strategies should also be assessed in diverse practice settings with diverse populations to understand generalizability and factors that influence it. Finally, we need to understand how to translate and feasibly deliver these evidenced-based strategies into health practice, through delivery, dissemination, and diffusion research.

The AHA's 2020 Goals include a new concept of cardiovascular health that directly incorporates metrics of lifestyle behaviors, including diet and PA habits, as defining health.²²⁵ Whereas further research is needed on several aspects of individual- and group-based interventions to improve diet and PA, a sufficient evidence base now exists to incorporate several specific strategies, as outlined in Table 4, into clinical practice. The promotion of these interventions should form a key component of strategies to achieve the AHA's 2020 Goals and improve the cardiovascular health of the population.