Background

Weight is commonly classified using the body mass index (BMI), which is calculated by dividing a person's weight in kilograms by their height in meters squared.1 Based on BMI, overweight is classified as having a BMI between 25 and 29, while obesity is classified as having a BMI of over 30.1,2 Obesity has become a global health issue, with worldwide obesity doubling since 1980. There are over 1.9 billion overweight adults worldwide, and of these, over 600 million are obese.1

The economic impact of obesity on the global gross domestic product is approximately $2 trillion.3 This amount ranks third, behind smoking and armed violence and war and terrorism, which are both estimated at $2.1 trillion.3 Costs related to obesity are described as direct or indirect. Direct costs are those for obesity-related medical care. In the United States (US), this cost is estimated at $147 billion dollars.2 Direct healthcare costs can increase quickly, as obesity is associated with an increased risk of cardiovascular disease, diabetes, osteoarthritis, depression and certain types of cancer.1,4 Indirect costs, such as work absenteeism, are estimated as high as $6.38 billion in the US.2

To compound the problem, the increasing number of obese adults also affects the weight status of children. It is estimated that one in five children in the US are overweight.5 This disease is occurring at an alarmingly young age, with the global estimates of overweight children under the age of five reaching 42 million.6 In addition, overweight preschool children are five times as likely to become overweight adults as normal-weight children.5 This is likely due to the fact that the adults in a child's life are the first teachers and have a heavy influence over food choices and exercise habits. It is reasonable to expect that the lifestyle choices of an adult who is overweight or obese will have a similar effect on the weight status of their children. Therefore, to curb this weight-related epidemic among all age groups, it is important to address the problems of adult overweight and obesity effectively.

Causes for the increased overweight and obesity prevalence and associated costs can be attributed to high-fat, high-calorie diets, and sedentary lifestyles.1 In addition, causes of overweight and obesity are multifaceted and complex, creating a difficult disease to treat effectively. Options available for obesity treatment include medication, surgery, and most importantly, lifestyle changes.4 Lifestyle changes, or modifications, are not only important during the initial weight loss treatment, but are critical for healthy weight maintenance.4 With the global increase in obesity prevalence, many countries have increased marketing strategies and clinical guidelines to promote healthy lifestyles. Obesity prevention recommendations are common in most countries including the US, Canada, China, Russia and Mexico.7 Australia has implemented a star rating system for food packaging to inform buyers of the food's overall nutritional profile.7 European countries are currently investigating ways to decrease marketing of unhealthy food, especially to children. These efforts include taxes on high-sugar, high-salt and high-fat foods and exercise promotions such as "Cycle to Work" in Iceland.7 For an intervention to be effective, however, a patient must be ready to change and engage in active participation in the weight-loss plan.8

Primary care providers (PCPs) are the front line in the fight against the preventable diseases of overweight and obesity. Primary care providers are commonly the healthcare providers from whom patients seek information and who manage patients' long-term treatment and complications.4 A promising approach to engaging patients in active participation in their health care and promoting readiness to change, and one that is ideally suited to the PCP, is patient-centered weight management counseling. In fact, patient perception of a working alliance with a provider has been shown to increase patient satisfaction and adherance.9 Patient-centered counseling broadens the traditional provider-patient relationship by including patient views and promoting patient input when deciding on treatment.10 This model views the relationship as a partnership, with the provider's and patient's knowledge being equally important. The provider holds the technical medical knowledge about the treatment options, while the patient brings perspective on how a treatment will fit into their current environment.10 Patient-centered counseling includes, but is not limited to, individual treatment plans, adaptive treatment strategies, motivational interviewing and shared decision making. These techniques allow a provider to explore the patient's views and lifestyle, and build rapport through non-judgmental communication and effective listening.11 Since obesity is a multifaceted disease, patient-centered communication is recommended to address stigmas, to manage barriers and to set mutually agreed upon goals leading to successful lifestyle modifications.12 Piatt et al. demonstrated the importance of patient input in weight loss education by including a self-selection variable when choosing the education method. This self-selecting group had the greatest average weight loss and was twice as likely to maintain the weight loss at the 18-month follow-up visit when compared to the randomly assigned intervention groups.13

As the rates of obesity continue to increase, it is clear that current weight management techniques must change. Primary care providers should play a central role in identifying obesity, assessing desire to change and arranging the appropriate treatment plan.8 The US Preventive Services Task Force (USPSTF) recommends that all adults are screened for obesity and those with a BMI of 30 or greater receive intensive, multicomponent behavioral interventions.14 However, previous systematic reviews examining weight loss treatment cited a lack of confidence in patient motivation and readiness to change.15 Patient-centered weight management offers a framework for implementation of behavioral weight loss interventions with acknowledgement of socio-cultural, economic and environmental issues unique to each person. There are current reviews that focus on obesity treatment combining lifestyle changes with medications and surgery and that examine the use of lifestyle modifications for patients with specific disease processes including cardiovascular disease, diabetes and non-alcoholic fatty liver disease.4,8,16-18 This systematic review is unique both in its purpose to examine the effectiveness of patient-centered weight management counseling and in examining this intervention in a primary care setting. No current systematic reviews on this topic have been identified during preliminary searching. Overweight and obesity are global health problems with drastic consequences. However, these disease processes are preventable with appropriate treatment. Lifestyle modifications are successful for weight loss and weight maintenance, but only if the changes are sustainable. This review will seek to determine the effectiveness of patient-centered weight management counseling provided by a PCP on changes in weight and lifestyle modifications.

Inclusion criteria

Types of participants

The current review will consider studies that include adults classified as overweight or obese. Classification as overweight or obese will be measured using BMI. A person with a BMI of 25-29 is considered overweight and a person with a BMI over 30 is considered obese. Although there are additional BMI classifications, such as super obese, the distinction between obese classification groups is not needed in this review since these participants would already be included per the requirement of having a BMI greater than 25. Studies included in this review must include participants who are at least 18 years old with a BMI of 25 or greater who are being treated in a primary care setting. Exclusion criteria include pediatric studies and studies conducted at specialty clinics. Studies will also be excluded if weight status is not determined by BMI or if the BMI of participants cannot be clearly determined to be over 25.

Types of intervention

The current review will consider studies that evaluate the use of patient-centered weight management counseling. Patient-centered weight management counseling includes individualized treatment plans, adaptive treatment strategies, motivational interviewing and shared decision making. To be included in this review, studies must include at least one of these strategies. All included studies will take place in a primary care setting. There is no minimum or maximum number of required patient interactions for studies to be included in this review. This approach will be compared to all other non-pharmacologic, non-surgical interventions and to those with no active intervention.

Outcomes

The current review will consider studies that include the following primary outcome measure: Weight change measured in BMI, pounds, kilograms, body fat percentage and waist circumference.

The current review will also consider studies that include the following secondary outcome measure: Lifestyle modifications, including eating habits and physical activity. Eating habits will be reported through food journaling and can include calorie counts and number of serving for each food group. Physical activity will be reported by time or by distance covered.

Types of studies

The current review will consider both experimental and epidemiological study designs including randomized controlled trials, non-randomized controlled trials, quasi-experimental, before and after studies, prospective and retrospective cohort studies, case-control studies and analytical cross-sectional studies for inclusion.

The current review will consider descriptive epidemiological study designs including case series, individual case reports and descriptive cross-sectional studies for inclusion.

Search strategy

The search strategy aims to find both published and unpublished studies. A three-step search strategy will be utilized in this review. An initial limited search of PubMed and CINAHL will be undertaken followed by analysis of the text words contained in the title and abstract, and of the index terms used to describe the article. A second search using all identified keywords and index terms will then be undertaken across all included databases. Third, the reference list of all identified reports and articles will be searched for additional studies. Studies published after 2003 in the English language will be considered for inclusion in this review. This date will include studies published after the original USPSTF recommendation for obesity screening for all adults and intensive interventions to promote sustained weight loss in obese individuals.

The databases to be searched include:

CINAHL, PubMed, Cochrane CENTRAL, SCOPUS, PsycINFO.

The search for unpublished studies will include:

Google Scholar, NYAM Grey Literature Collection, OAIster, ProQuest Dissertations and Theses and Mednar.

Initial keywords to be used will be:

Weight management counseling.

Weight management

Weight loss

Overweight

Obesity

Non-pharmacologic

Lifestyle change

Behavior modification

Behavioral therapy

Patient-centered care

Patient-centered counseling

Patient-centered communication

Shared decision making

Individualized care/treatment plans

Adaptive treatment strategies

Motivational interviewing

Primary care

Assessment of methodological quality

Papers selected for retrieval will be assessed by two independent reviewers for methodological validity prior to inclusion in the review using standardized critical appraisal instruments from the Joanna Briggs Institute Meta Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI) (Appendix I). Any disagreements that arise between the reviewers will be resolved through discussion or with a third reviewer.

Data extraction

Data will be extracted from papers included in the review using the standardized data extraction tool from JBI-MAStARI (Appendix II). The data extracted will include specific details about the interventions, populations, study methods and outcomes of significance to the review question and specific objectives.

Data synthesis

Quantitative data will, where possible, be pooled in statistical meta-analysis using JBI-MAStARI. All results will be subject to double data entry. Effect sizes expressed as odds ratio (for categorical data) and weighted mean differences (for continuous data) and their 95% confidence intervals will be calculated for analysis. Heterogeneity will be assessed statistically using the standard Chi-square and also explored using subgroup analyses based on the different study designs included in this review. Where statistical pooling is not possible, the findings will be presented in narrative form including tables and figures to aid in data presentation where appropriate.

Acknowledgements

The current review will also contribute to the Doctor of Nursing Practice degree for the primary investigator, RL.

Appendix I: Appraisal instruments

MAStARI appraisal instrument

Appendix II: Data extraction instruments

MAStARI data extraction instrument

References