Current public health estimates indicate that approximately 70% of U.S. adults are overweight or obese (20), and half of these individuals have at least one or more chronic health conditions (4). Research shows that U.S. adults understand the impact of obesity on overall health, yet few consult with a health professional about their weight concerns (11). The Centers for Disease Control and Prevention (CDC) states that successful obesity prevention and weight management programming requires an integration of nutrition and physical activity (PA) (5) in accordance with clear evidence (2,7). Although research indicates that the value of these strategies is widely understood, many report multiple attempts at weight loss (11), indicating a lack of long-term success when using these strategies without professional guidance. Therefore, providing consumers with accurate information and practical skills on healthful eating and PA that will help manage weight and prevent or treat chronic disease is imperative.
Registered dietitian nutritionists (RDNs) and ACSM certified exercise professionals (ACSM Certs) are in a unique position to provide consumers with accurate and useful information and behavioral counseling to help manage weight and/or prevent or treat chronic disease (9). However, despite the interrelated and synergistic effect of diet and PA on energy balance, most professionals are trained with an expertise in one area with little education and expertise in the other. Few RDNs are required to take coursework in exercise science, PA, or the role of exercise in chronic disease prevention or treatment; likewise, most ACSM Certs take limited coursework in nutrition (9).
Use of an integrated approach to the education of nutrition and exercise science professionals stressing the dynamic nature of energy balance will provide a broader understanding of each discipline than can be achieved through taking a single course in the opposite discipline (9). This integration, along with improved collaboration between the professions, can improve the delivery of services to the consumer and weight management outcomes (9). To foster such collaboration, each must understand and respect the knowledge, skills, and scope of practice (SOP) of the other profession (9).
To address this issue, in 1999, the American College of Sports Medicine (ACSM), the Academy of Nutrition and Dietetics (Academy), and International Food Information Council (IFIC) Foundation surveyed a national sample of Academy and ACSM members to identify practices and attitudes of each profession (3). This phone survey reached 306 Academy members and 317 ACSM members. Results showed that approximately half of RDN respondents reported it was important to encourage regular PA (51%), whereas more than half of exercise professional respondents identified reduction of fat intake as a key message (55%) and 43% encouraged a balanced diet (3). In 2015, the same organizations collaborated on an online survey to determine whether these practices and attitudes had changed. This survey targeted practicing RDNs (n = 3,715) and ACSM Certs (n = 1,759), representing a 9.1% and 7.0% response rate, respectively (10). Students and individuals reporting credentials in both areas were eliminated from the analysis. Table 1 provides the general demographics of the survey participants.
Participants were asked questions regarding credible sources of information on healthful eating, PA, and weight loss; familiarity with and knowledge of each professions’ SOP and that of the other profession; attitudes toward sale of dietary supplements and PA resources; the frequency with which each provides advice on the opposite topic and refers to other professionals; and their perception of the credibility of the other profession. For the purposes of this survey, healthful eating was defined as “a dietary pattern to meet nutrient needs for an individual’s health concerns,” and PA “encompasses both unplanned and planned physical activity (exercise) (10).”
In the following section, we summarize the results of this survey; the complete survey results are provided elsewhere (10). Interestingly, a wide discrepancy was observed in each profession’s perception of who is the expert in the area of weight management. We therefore describe the challenges of providing evidence-based weight management services and identify ways in which RDNs and ACSM Certs can work together to best meet each client’s needs.
Do RDNs Give Physical Activity Guidance to Clients?
Overall, more than 83% of RDNs reported that providing PA guidance based on the 2008 Physical Activity Guidelines for Americans (PAG) was within their SOP (10). A majority (56.6%) also reported that providing guidance on PA to achieve a client’s weight goals was within their SOP, whereas a smaller percentage considered providing specific guidance on strength training (13%) or recovery from injury (23%) to be within their scope. Although 63.8% of ACSM Certs consider providing PA guidance based on the 2008 PAG to be within the RDN’s SOP, only 24% thought that giving PA guidance for weight management was within the RDN’s SOP (10).
Do ACSM Certified Exercise Professionals Give Healthful Eating Advice to Clients?
More than 76% of ACSM Certs reported that they regarded it within their SOP to provide their client with healthful eating advice based on the Dietary Guidelines for Americans, and 81% felt they could provide guidance on locating credible healthful eating information. Overall, 43.9% of ACSM Certs reported that providing guidance on healthful eating to achieve a client’s weight goal was within their SOP, and 13.7% felt it was within their SOP to provide healthful eating advice for a specific disease or condition. Conversely, only 23.8% of RDNs thought that it was within the ACSM Cert SOP to provide healthful eating advice to manage weight, and only 4% felt it was within their SOP to provide healthful eating advice for a specific disease or condition (9).
How Does Each Profession Perceive Their Expertise and That of the Other Profession in the Area of Diet and Physical Activity?
As shown in the Figure, RDNs and ACSM Certs are in agreement that ACSM Certs are the most credible source of PA information for consumers, and that the RDN is the most credible source of information for healthy eating.
Who Can Provide the Best Advice to Clients About Weight Management?
RDNs overwhelmingly see themselves as the most credible source of weight loss information for clients (95%), whereas results from ACSM Certs are mixed, with 46% identifying the RDN as the most credible source of weight loss information for clients and 42% reporting that they were the best source (See Figure). Notably, RDNs see themselves as the weight management experts, yet they typically have little training in the area of PA for weight management. Conversely, a high percentage of ACSM Certs see themselves as the experts in weight management despite their lack of extensive training in nutrition and food science.
Competency Varies With Level of Expertise
ACSM and the Academy both offer a range of credentials based on level of education and experience. ACSM Certs requirements vary from the Certified Personal Trainer, which requires a high school diploma or equivalent (https://certification.acsm.org/acsm-certified-personal-trainer), to the ACSM Certified Exercise Physiologist, which requires a Bachelor’s degree in Exercise Science (https://certification.acsm.org/acsm-certified-exercise-physiologist) and the ACSM Clinical Exercise Physiologist, which requires a Bachelor’s degree in Exercise Science along with clinical exercise experience (https://certification.acsm.org/acsm-certified-clinical-exercise-physiologist). ACSM’s Registered Clinical Exercise Physiologist requires a Master’s-level degree in Exercise Science, Exercise Physiology, or Kinesiology and clinical experience (https://certification.acsm.org/acsm-registered-clinical-exercise-physiologist). All RDNs are required to hold a Bachelor’s degree, complete coursework approved by the Accreditation Council for Education in Nutrition and Dietetics (ACEND) of the Academy including nutrition science, medical nutrition therapy, biochemistry, food science, counseling skills, and behavior modification (http://www.eatrightacend.org/ACEND/content.aspx?id=6442485414). They also must successfully complete a minimum of 1,200 hours in a supervised practice program before taking and passing a national examination administered by the Commission on Dietetic Registration (CDR). Both RDNs and ACSM Certs must complete annual continuing education hours to maintain their registration or certification. Upon completing two years of practice, RDNs become eligible to earn advanced certification through CDR in sports nutrition as a certified specialist in sport dietetics (CSSD) (http://www.scandpg.org/sports-nutrition/be-a-board-certified-sports-dietitian-cssd/) or can complete certificate programs in adult weight management (https://www.cdrnet.org/weight-management-adult-program) or childhood and adolescent weight management (https://www.cdrnet.org/weight-management-childhood-adolescent-program). Only the CSSD requires knowledge of exercise physiology, but all require knowledge of the role of PA in weight management. It is important to note that regardless of advanced training and/or certification, RDNs would not be working within their SOP if they provided a specific exercise training program to a client without also being a certified exercise professional. The interested reader is referred to an extensive table outlining educational requirements published elsewhere (9).
Evidence-Based Weight Management
Energy balance is dynamic in nature, and intervening on one side of the energy balance equation affects the other side in a variety of ways that are only beginning to be understood (9). Despite the lack of extensive training in the opposite field, ACSM Certs and RDNs working in weight management must have a thorough grasp of the science of dynamic energy balance, and each must address both sides of the energy balance equation (9). In addition, both professionals need the skills required to understand the specific needs of their client and address behavioral issues necessary to affect positive change.
The obesogenic environment and exposure to misinformation through the Internet and media add to the challenges faced by would-be weight reducers and must be addressed. Although research clearly demonstrates the complexities involved in designing appropriate interventions for weight loss and maintenance, incomplete and out-of-context summaries of research articles publicized by the media muddy the picture for the layperson. In one recent example, “To Keep Obesity at Bay, Exercise May Trump Diet,” published in the New York Times (NYT) (Reynolds May 4, 2016) reported on an animal study published in ACSM’s flagship journal, Medicine & Science in Sports & Exercise®. In this study, young normal weight but obesity-prone rats were placed in one of three groups: exercise, calorie restricted, or control (19). The diets of the calorie-restricted rats were adjusted based on daily weights to ensure similar weight loss to the exercise group, which allowed researchers to compare the metabolic effects of weight loss from exercise versus caloric restriction. Both exercise and caloric-restricted animal groups experienced metabolic improvements with weight loss, but the exercise group also experienced improvements in fat oxidation and insulin resistance that typically occur with exercise training. Overall, both groups experienced metabolic improvements with weight loss, but the exercise group experienced additional metabolic benefits beyond those seen with caloric restriction alone. Although this study represents an important contribution to the literature, the misleading title of the NYT article inferred more effective weight loss from exercise versus diet, contributing to the misunderstandings surrounding this area of enormous public interest (8). Such misrepresentations demonstrate why both ACSM Certs and RDNs must be able to critically evaluate media interpretations of research and place them in context for their clients.
A precise prescription for successful weight loss does not exist for either diet or PA. Exercise without a reduction in energy intake, although providing overall health benefits, has been found to result in limited weight loss (7,15,16). Conversely, creating an energy deficit by restricting caloric intake alone will result in weight loss but is likely to have negative metabolic consequences such as excessive loss of lean mass and decreases in resting metabolic rate that will make maintenance difficult (2,13).
The CDC public health guidelines for weight loss include a reduction in energy intake by 500 to 1,000 kcals per day and inclusion of 60 to 90 minutes of moderate-intensity PA most days of the week, thus addressing both energy intake and energy expenditure (5). The inability of researchers to identify a single optimal protocol beyond these broad guidelines is likely due to the substantial individual variability observed in response to weight loss interventions, highlighting the need for skilled assessment and implementation of individualized nutrition and PA strategies.
ACSM and the Academy each provide guidance for evidence-based weight management strategies (1,7,12). Tables 2 and 3 illustrate the guidance that each organization provides to their professionals related to weight management, with the documents focusing on what their respective professionals can do to help clients lose weight, yet they do not outline how the two professions should or could work together.
Working Together to Integrate Nutrition and Physical Activity
ACSM Certs and RDNs are committed to using an evidence-based approach to weight management, thus helping clients develop healthy eating and PA patterns that will enable them to achieve and maintain a healthy body weight and reduce their risk of chronic disease. Our survey found that 51.1% of RDNs referred clients to ACSM Certs for credible information on PA, and 72.2% of ACSM Certs referred clients to RDNs for credible information on healthful eating (10). The most frequent reason cited for referral selection was trust in the credential, and most reported science-based recommendations and individualized attention as the primary benefit to clients by both RDNs (84.7%) and ACSM Certs (90.9%) (10).
Working together to meet their client’s respective needs strengthens both the RDN and ACSM Cert. Furthermore, focusing on one’s own area of expertise and knowing when it is appropriate to refer to the other expert maintains credibility for each respective profession. Ultimately, it is this professionalism that helps clients persevere in making progressive changes rather than giving up prematurely, a victim of unrealistic expectations generated in part by advertisements for weight loss foods and products and some media. By working together, the two professionals can strengthen the public health message that a successful weight management program is a function of both purposeful PA and prudent diet changes because each intrinsically enhances the other.
Working together to meet their client’s respective needs strengthens both the RDN and ACSM Cert. Furthermore, focusing on one’s own area of expertise and knowing when it is appropriate to refer to the other expert maintains credibility for each respective profession. Ultimately, it is this professionalism that helps clients persevere in making progressive changes rather than giving up prematurely, a victim of unrealistic expectations generated in part by advertisements for weight loss foods and products and some media.
Through networking and sharing information, RDNs and ACSM Certs can build relationships that enhance the weight management outcomes of their clients. Some suggestions to begin working together are provided as follows:
- Make an effort to find members of the opposite profession who work in weight management. Get to know the type of services provided and insurance policies that cover these services. These interactions will increase awareness of the services available to your client and the trained professionals you can make referrals to.
- Attend an Academy or ACSM meeting, particularly when it is in your area. Both offer sessions on nutrition and PA. In this way, you become aware of research and experts in the other profession and can begin to build bridges.
- Invite members of the opposite profession to presentations or workshops in your area that they may benefit from and ask them to do the same for you.
- Speak with individuals and identify those with whom you share a philosophy toward weight management to make client referrals.
This dualistic approach combining the talents and expertise of both RDNs and ACSM Certs makes realistic weight loss goals and achievable lifestyle changes possible and helps steer clients away from popular but unfounded claims such as “lose 40 pounds in 40 days!”
When to Refer
RDNs work within their SOP when they encourage adherence to the 2008 Physical Activity Guidelines (18), but should refer to an exercise professional when a client needs assistance in implementing PA guidelines, would benefit from a risk assessment, baseline testing, individualized exercise program, or when safety is a concern (12,14). Referral to an ACSM Cert may be especially important for obese clients needing extra assistance in meeting their PA goals in a safe and comfortable manner (6).
ACSM Certs work within their SOP when they encourage adherence to the Dietary Guidelines for Americans (7) (Table 4). The job task analysis of the ACSM Cert addresses the need for collaboration between professions for optimal outcomes, but specific criteria for identifying individuals for referral to a nutrition professional have not been developed. However, the ACSM’s Position Stand for Weight Management includes the following statement:
- “Exercise professionals should be cautioned regarding the provision of dietary advice to overweight and obese adults. In particular, caution is advised when chronic disease risk factors or known chronic disease are present. Providing specific diet recommendations may be outside the SOP for the exercise professional, and the appropriate course of action may require referral to a registered dietitian” (7) (pg 164).
The following criteria are suggested for identifying individuals who would benefit from referral to an RDN:
- Need for individualized diet prescription beyond Dietary Guidelines for Americans (https://health.gov/dietaryguidelines/2015/) and MyPlate recommendations (https://www.choosemyplate.gov/dietary-guidelines).
- Need for medical nutrition therapy including, but not limited to, diabetes, hypertension, cardiovascular disease, and gastrointestinal disorders.
- Need for skilled counseling to prioritize dietary changes and overcome obstacles to behavior change related to food choices and meal patterns.
- Concern about possible disordered eating/unhealthy relationship with food.
Not every client will need a team approach. For some, encouraging adherence to the Dietary Guidelines for Americans and the 2008 Physical Activity Guidelines will enable the client to achieve his or her health and fitness goals.
ACSM Certs and RDNs are each challenged by the client who believes that the best way to achieve weight goals is to spend hours in the gym while eating as little as possible. Together, both professionals can discuss dynamic energy balance and the need for a diet strategy that supports PA and an active lifestyle. As clients achieve greater success through science-based strategies delivered by professionals, the popularity of quick-fix schemes may diminish and the health of the nation improve.
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Keywords:© 2017 American College of Sports Medicine.
Scope of Practice; Physical Activity; Nutrition; Weight Management; Dynamic Energy Balance