Note from the National Guideline Clearinghouse (NGC) and the Institute for Clinical Systems Improvement (ICSI): For a description of what has changed since the previous version of this guidance, refer to "Summary of Changes -- November 2006."

The recommendations for the prevention and management of obesity in mature adolescents and adults are presented in the form of an algorithm with 12 components, accompanied by detailed annotations. An algorithm is provided for Prevention and Diagnosis. Clinical highlights and selected annotations (numbered to correspond with the algorithm) follow.

Class of evidence (A-D, M, R, X) and conclusion grade (I-III, Not Assignable) definitions are repeated at the end of the "Major Recommendations" field.

Clinical Highlights

• Obesity is a chronic disease that is multi-factorial with complex political, social, psychological, environmental, economic, and metabolic causes and consequences. Obesity affects essentially every organ system in the body. Health consequences increase across the body mass index (BMI) span, not just for the extremely obese. (Annotation #1)
• Calculate the BMI; classify the individual based on the BMI categories. Educate patients about their BMI and their associated risks. (Annotation #1, 2)
• Effective weight management strategies are available and include nutrition, physical activity, lifestyle changes, medication, and surgery. (Annotation #9)
• The physician should follow the 5 A's (Ask, Advise, Assess, Assist, Arrange). Physician intervention can be effective, the physician can have an important influence, and successful weight management is possible. (Annotation #8, 9)
• Weight management requires a team approach. Be aware of clinical and community resources. The patient needs to have an ongoing therapeutic relationship and follow-up with a health care team. Weight control is a lifelong commitment and the health care team can assist with setting specific goals with the patient. (Annotation #8, 9)
• Beyond their clinical role, primary care physicians should be aware of their roles as  community leaders and public health advocates. (Annotation #12)

Prevention and Diagnosis Algorithm Annotations

1. Measure Height, Weight, and Calculate BMI (Preferably Annually for Screening and as Needed for Management)

   Key Points:

   • Health consequences exist across the BMI span and obesity is a multi-factorial chronic disease.
   • BMI should be calculated preferably annually for screening and as needed for management.
   • BMI calculation extends to all age groups. Adolescents less than Tanner stage 5 and children should be evaluated by available growth charts.

   1a. Calculate BMI

   Calculate the BMI at least annually for screening and as needed for management. Classify it based on the BMI categories. Educate patients about their BMI and associated risks for them.

   BMI = weight (kg)/height squared (m²) or (pounds x 703)/inches²

   Adult BMI Categories

   BMI	Category
   Less than 18.5	Underweight
   18.5 to 24.9	Normal weight
   25 to 29.9	Overweight
   30 to 34.9	Obese -- class I
   35 to 39.9	Obese -- class II
   40 or more	Extreme obesity -- class III

   Mature Adolescents

   Physiologically speaking, maturation refers to the tempo of sexual development during puberty. The physiologic progression of pubertal stages proceeds in a definable sequence but the age of onset and the rate of progression exhibit significant inter-individual variability. Pubertal stages from prepuberty to mature adult have been categorized by Tanner in 1962. Tanner identified 5 stages of maturation based on progressive changes in external genitalia.

   For the purpose of this guideline, Tanner stage 5 will be considered physiologic maturity. The extension of guideline medication and surgery recommendations to this population is physiologically feasible. However, given the complexity of obesity variables and psychosocial issues, the use of medications and surgery in physiologically mature but younger adolescents needs to be discussed and decided within provider community practice standards.

   Adults may be sub-classified using absolute values for BMI. These absolute cutoffs for BMI may also be used for the sexually mature (Tanner stage 5) fully grown adolescent. However, absolute cut-off values cannot be directly applied to all adolescent patients. Adolescence is characterized by variable growth rate and variable tempo for sexual maturation. This variability in height and body composition complicates the determination of absolute BMI cutoffs for a normally changing individual. Growth, maturation, and ethnic differences also make it difficult to determine a definite chronologic age for using adult BMI criteria.

   The normative value for pediatric and adolescent BMI is highly age dependent.

   See Appendix A, "Body Mass Index-For-Age Percentiles" in the original guideline document.

   Since BMI is based on height and weight, it reflects the underlying variability in these features at a given chronologic age. Given the confounding effects of growth and maturation, the traditional pediatric approach to establishing normative values is to develop percentiles based on a reference population. The National Health and Nutrition Examination Survey (NHANES) has been done three times: NHANES I (1963-1970), II (1976-1980), and III (1988-1991). More recently, Rosner, et al. combined data from nine United States studies, including NHANES II and III, on over 66,000 participants. From this data set they determined BMI percentiles for ages 5-17. BMI tables are presented for boys and girls with ethnic subsets: Asian, Black, Hispanic, and White. United States weighted mean values are also provided (http://www.cdc.gov/nchs/nhanes.htm). Medical definitions of obesity may differ from cultural perceptions.

   In the pediatric literature, the "at risk" group has been defined as the 85th percentile. The 95th percentile has been used to identify the obese or grade 2 overweight individual. Specific cutoff values for a given gender, age and ethnic group are available from the previously mentioned percentile tables.

   A BMI calculation is worthwhile in the growing patient because it provides a reference point for future comparison. Subsequent observations establish a relative trajectory for this index of obesity. Although there are no standards for rate of change of BMI per year, a rapid increase or decrease warrants clinical attention. The separation between 50th and 75th percentile is approximately 2-3 BMI units for adolescent girls across ethnic groups. Adolescent boys have approximately 2 BMI units difference between these percentiles. An annual increase of greater than 3 units suggests excessive gain.

   The clinical significance of an abnormal or rapidly changing BMI is assessed with the following in mind:

   • BMI is not a direct measure of adiposity. It is a derived value that correlates well with total body fat and markers of secondary complications (e.g., hypertension and dyslipidemia).
   • An abnormally high BMI does not address the distribution of body fat (i.e., central vs. peripheral or visceral vs. subcutaneous). Central or visceral fat carry greater risk for morbidity and mortality.
   • Waist circumference (as recommended by the National Heart Lung and Blood Institute [NHLBI], see Annotation #2 in the original guideline document) provides an additional dimension for assessing visceral adiposity and clinical risk.
   • Metabolic assessment is important in the patient at risk, especially if there is a family history for heart disease or type 2 diabetes mellitus.
   • Clinical conditions associated with adolescent obesity are found in Table 4 in the original guideline document. Depression, anxiety, eating disorders, and sexual abuse are also important clinical associations with adolescent obesity.

   Evidence supporting this recommendation is of classes: D, R

2. Assess for Major and Minor Comorbid Conditions

   Key Points:

   • It is important to assess for other conditions as treatment decisions and outcomes may be influenced by their presence.
   • Waist circumference greater than or equal to 40 inches for males and greater than or equal to 35 inches for females is an additional risk factor for complications related to obesity.
   • For depression and eating disorders, brief screenings should be conducted if appropriate.
   • Assessment should include a complete medical history to identify medications that may induce weight gain or interfere with weight loss.

   Comorbid Condition Assessment

   Comorbid Condition	BMI
   	25 to 30	30 to 35	35 to 40	40+
   0	Lifestyle changes and behavioral management	Lifestyle changes and behavioral management. Consider drug therapy	Lifestyle changes and behavioral management. Consider drug therapy	Lifestyle changes and behavioral management. Consider drug therapy and/or surgical evaluation.
   1-3 minor comorbid conditions	Lifestyle changes and behavioral management	Lifestyle changes and behavioral management. Consider drug therapy	Lifestyle changes and behavioral management. Consider drug therapy and/or surgical evaluation.	Lifestyle changes and behavioral management. Consider drug therapy and/or surgical evaluation.
   Major comorbid conditions OR more than 3 minor comorbid conditions	Lifestyle changes and behavioral management. Consider drug therapy. The Food and Drug Administration (FDA) approves drug therapy only for BMI greater than 27.	Lifestyle changes and behavioral management. Consider drug therapy.	Lifestyle changes and behavioral management. Consider drug therapy and/or surgical evaluation.	Lifestyle changes and behavioral management. Consider drug therapy and/or surgical evaluation.

   Minor Comorbid Conditions

   • Cigarette smoking
   • Hypertension (blood pressure [BP] greater than or equal to 140/90) or current use of antihypertensives^
   • Low-density lipoprotein (LDL) cholesterol greater than 130 mg/dL^
   • High-density lipoprotein (HDL) cholesterol less than 40 mg/dL
   • Pre-diabetes*^
   • Family history of premature coronary artery disease (CAD)
   • Age greater than or equal to 65 years for males
   • Age greater than or equal to 55 years for females or menopausal females

   Major Comorbid Conditions

   • Waist circumference (males >40 inches, females >35 inches)^
   • Established coronary artery disease
     • History of myocardial infarction
     • History of angioplasty
     • History of coronary artery bypass graft (CABG)
     • History of acute coronary syndrome
   • Peripheral vascular disease
   • Abdominal aortic aneurysm
   • Symptomatic carotid artery disease
   • Type 2 diabetes mellitus
   • Obstructive sleep apnea

   * The term pre-diabetes has recently been adopted by the American Diabetes Association and others, and refers to those who have a fasting plasma glucose of 100 mg/dL to 125 mg/dL inclusive, as well as those with a two-hour post 75 gram oral glucose tolerance test value of greater than or equal to 140 mg/dL to 200 mg/dL.

   ^ The clustering of these symptoms has been described as the metabolic syndrome.

   Other Conditions

   Clinicians may use the waist circumference as a measure of central adiposity. Men with waist circumferences greater than or equal to 40 inches (102 cm) and women with a waist circumference greater than or equal to 35 inches (88 cm) are at increased risk for cardiovascular disease.

   In the Health Professional Follow-up Study, overall and cardiovascular mortality in men increased linearly with baseline BMI in younger men (those initially younger than 65 years) and had no relationship with BMI in older men (those initially at least 65 years); by contrast, waist circumference predicted risk for overall and cardiovascular mortality among the younger men, and predicted risk for cardiovascular death among older men.

   The Iowa Women's Health Study found that the waist-hip ratio was a better predictor of total cardiovascular mortality than BMI, and that even in women in the lowest BMI quintile, there was a markedly increased risk for diabetes if they also had a high waist-hip ratio.

   Waist circumference is an additional risk factor for complications related to obesity for males measuring greater than or equal to 40 inches, females greater than or equal to 35 inches. While the work group acknowledges potential difficulty implementing the measurement of waist circumference, evidence shows the importance of measuring waist circumference because of increased cardiovascular risk.

   Evidence supporting this recommendation is of class: B, C, D

   Screening for Depression

   The evidence showing the linkage between depression and obesity is mixed. Higher rates of depression have been found in severely obese people, especially younger women with poor body image. It is difficult to study whether the depression is secondary to the obesity or to existing comorbid conditions. Weight loss often leads to improvement of depression scores.

   Depression is identified more often in obese women and teenagers and is less likely to be diagnosed in men. Depression in the elderly is often associated with weight loss while depression in younger females can be associated with weight gain.

   Depression has been associated with poor weight loss outcomes. Bariatric surgery patients with poorly managed depression or anxiety are at greater risk for weight regain within the first five postoperative years. One explanation for this may be found in a line of research investigating biological pathways that link depressive symptomatology to increased adiposity and weight gain. Weight loss studies have often excluded people with depression. More studies to address this issue are warranted.

   Evidence supporting this recommendation is of classes: B, C, D, R

   Screening for depression can include asking the following questions.

   Over the past month, have you been bothered by:

   1. Little interest or pleasure in doing things?
   2. Feeling down, depressed, or hopeless?

   If the patient answers "yes" to either one of the above questions, consider using a questionnaire to further assess whether the patient has sufficient symptoms to warrant a full clinical interview and a diagnosis of clinical major depression. An example of such a questionnaire is the (Patient Health Questionnaire) PHQ-9.

   This should not be considered a comprehensive screening for depression, which is beyond the scope of this guideline. See the National Guideline Clearinghouse (NGC) summary of the Institute for Clinical Systems Improvement (ICSI) guideline Major Depression in Adults in Primary Care for more information.

   Screening for an Eating Disorder

   Eating disorders, particularly binge eating disorder, may complicate the treatment of obesity.

   Screening for eating disorders can include asking the following questions:

   1. Do you eat a large amount of food in a short period of time -- like eating more food than another person may eat in, say, a two-hour period of time?
   2. Do you ever feel like you can't stop eating even after you feel full?
   3. When you overeat, what do you do? (e.g., Have you ever tried to "get rid of" the extra calories that you've eaten by doing something like: Take laxatives? Take diuretics [or water pills]? Smoke cigarettes? Take street drugs like cocaine or crank? Make yourself sick [induce vomiting])?

   If the patient answers "yes" to any of the above questions, consider further evaluation or a referral to a dietitian or a behavioral health specialist who specializes in eating disorders or in health psychology and working with bariatric patients.

   More comprehensive screening tools include the SCOFF, ESP, or EAT.

   Screening for Medication Use That Contributes to Weight Gain

   The assessment of the obese patient should include a complete medication history to identify medications that may induce weight gain or interfere with weight loss including antidiabetic medication (insulin, insulin secretagogues, metformin, alfa-glucosidase inhibitors, thiazolidinediones) and psychotropic drugs. For more information regarding medications associated with weight gain, refer to the original guideline document.

5. Advise Weight Maintenance and Manage Other Risk Factors

   Key Points:

   • It is important to address the issue of weight maintenance for those with BMI in the normal range.
   • Weight management includes physical activity, nutrition, and behavior management strategies.

   Lifetime risk of obesity is high for residents of the U.S. Lifetime risk of diabetes is about 30% for men and 35% for women, and lifetime risk for obesity is higher than this.

   Therefore, it is important to address the issue of weight maintenance for those with BMI in the normal range (18.5 to 24.9).

   Successful weight management requires a lifestyle approach that integrates physical activity, nutrition, behavioral management, and attention to psychosocial needs.

   • First, encourage regular physical activity at recommended levels. Regular physical activity is strongly related to maintaining normal weight. In selecting types of physical activity, it is important to consider the age of the patient, musculoskeletal limitations, and availability of exercise facilities. For inactive patients, this may include as little as 10 minutes of physical activity a day. Ideally, 30 to 60 minutes of moderate physical activity on most days of the week is recommended. However, for those who have lost a considerable amount of weight, higher amounts of physical activity may be required for weight maintenance. Enjoyment and variety of physical activity are also key features for adherence.
   • Second, provide structured lifestyle modification suggestions that include specific nutrition recommendations, educational sessions, and frequent contact with health-care providers such as a dietitian. Focus on calorie balancing, using a combination of decreased caloric intake with increased calorie expenditure. Include nutrition education (i.e., interpreting food labels); managing restaurant and social eating situations; making healthy, nutritious food choices; using portion control; and recipe modification.

     There is considerable evidence that individuals consuming low-fat, low-calorie diets are successful at maintaining weight loss for 12 months and longer. Data from the National Weight Control Registry demonstrates that successful weight-maintainers consume a low-calorie diet containing approximately 40 g fat (24% of calories), 200 g carbohydrate (56% of calories), and 70 g protein (19% of calories). A low fat diet (25 to 30% calories from fat) is considered the conventional therapy for treating obesity.

   • Third, encourage behavior management strategies that may include weekly weight checks, food journals, and monitoring daily routine that focuses on a balanced lifestyle. Balance includes: (a) eating a nutritionally-balanced breakfast soon after awakening and eating balanced meals at regular intervals thereafter, (b) incorporating fun physical activity into the day, and (c) scheduling the week to include rest, play, and social interactions along with work, school, and family responsibilities.

     Specific behavioral strategies to promote behavior change include: (a) self-monitoring some aspect of behavior which, in itself, typically results in behavior change; (b) non-food rewards and positive reinforcements; (c) reminders; (d) stimulus control (changing social or environmental cues that trigger eating behavior); (e) stress management and problem solving; and (f) helping patients believe they can be successful.

   Evidence supporting this recommendation is of classes: C, R

8. Assess Readiness to Lose Weight

   Key Points:

   • Knowing the patient's readiness to change can help the provider understand a patient's level of motivation and how to tailor communication about weight loss.
   • Patients need to set realistic, achievable goals and be held accountable to practice new behaviors that produce and maintain weight loss.

   Introduction to Weight Management/Lifestyle Change

   Weight management is a skill. Patients need to set realistic, achievable goals and to be held accountable to practicing the new behaviors that produce and maintain weight loss. Record keeping or self-monitoring of progress on specific behaviors is key to successful weight management. Strategies to reduce calorie intake are to incorporate more fruits and vegetables into meals and snacks, make lower-calorie, healthy choices at the grocery store and in social settings, and become more aware of portion sizes consumed. Additionally, portion-controlled, calorie-controlled meal replacements may be used. Every effort needs to be made to incorporate more physical activity on a daily basis.

   Patients and physicians must realize that the culture we live in continues to make eating less and being more physically active extremely challenging. It is easy for patients to become overwhelmed by the process if they believe all they need is willpower. It is discouraging if they think they have to quit eating all of their favorite foods and/or do hours of grueling exercise. It is even more challenging if they have a high level of stress in their lives.

   The physician should follow the 5 A's (Ask, Advise, Assist, Assess, Arrange). Physician intervention can be effective, the physician can have an important influence, and successful management is possible.

   • ASK about, and measure height and weight. Implement an office wide system to ensure that for every patient, preferably on an annual basis, weight is measured, body mass index is calculated, and that patients are educated about their BMI and risk status.
   • ADVISE to lose weight. In a clear, strong, but sensitive and personalized manner, urge every overweight or obese patient to lose weight.
   • ASSESS readiness to lose weight. Ask every overweight or obese patient if he or she is ready to make a weight loss attempt at the time (e.g., within the next 30 days).
   • ASSIST in weight loss attempt. Help the patient with a weight loss plan. Refer to appropriate resources
   • ARRANGE follow-up. Schedule follow-up contact, either in person or via telephone.

   Refer to the original guideline document for more detailed information on the 5 As.

   Evidence supporting this recommendation is of classes: A, B, C, M, R

   See Annotation #12, "Reassess Goals and Risk Factors and Counsel Regarding Weight Maintenance."

9. Negotiate Goals and Management Strategy to Achieve Weight Loss. Refer to Risk Appropriate Resources as Needed

   Key Points:

   • Nutrition recommendations include calorie reduction by evaluating portion size and number of servings recommended in the United States Department of Agriculture (USDA) Food Guide Pyramid.
   • The physiological effects of physical activity greatly depend on the frequency, duration, and intensity of movement.
   • Pharmacotherapy, when used for six months to one year, along with lifestyle modification including nutrition and physical activity, can produce weight loss in obese adults.
   • Bariatric surgery is indicated in carefully selected patients with a BMI greater than or equal to 40 or 35 to 39.9 who are at a very high absolute risk for increased morbidity or premature mortality (see the Table in Annotation #2 above). Patients are to be motivated, well-informed in disease management, psychologically stable, and accepting of operative risks

   Management Recommendations Based on BMI/Risk of Disease

   BMI	25 to 29.9	30 to 34.9	35 to 39.9	>40
   Risk	Low	Moderate	High	Severe
   Nutrition	X	X	X	X
   Physical Activity	X	X	X	X
   Behavioral Management	X	X	X	X
   Medication	*X	X	X	X
   Surgery			*X	X

   *May be considered if concomitant obesity-related risk factors or diseases are present.

   Nutrition (Balanced healthy eating plan or lower calorie balanced eating plan)

   1. Encourage at least 5 servings of fruits and vegetables per day, whole grains with a fiber intake of 35 grams or more daily, less than or equal to 30% of calories from fat (7 to 10% as saturated and trans fat).
   2. For weight loss, encourage calorie reduction by evaluating portion sizes and number of servings recommended.
   3. Provide tips for managing eating in social situations, dining out, take-out foods, and food label reading.
   4. Provide referral to a dietitian, nutritionist, or structured medically supervised nutrition program if available.

   Refer to the original guideline document for additional information on Nutrition Assessment and Therapy, including the following topics:

   • Diet history or eating pattern history
   • Nutrition assessment
   • Nutrition recommendations
   • Nutrition outcomes and goals

   Physical Activity

   1. Minimally, all patients should be encouraged to do at least 10 minutes of physical activity above what they are already doing each day and gradually increase the amount of time, followed by an increase in intensity.
   2. Ideally, all patients should meet the current recommendations of 30 to 60 minutes of moderate intensity activity on most days per week.
   3. Patients with chronic activity limitations (e.g., arthritis, respiratory dysfunction, neuropathy, morbid obesity) should be evaluated and managed to establish or enhance patient mobility.
   4. Provide tips for adding small bouts of physical activity to daily activities, for example, taking the stairs, parking farther away, exercising while watching TV. Activity breaks from screens (TV, computer, other media screens) is also important.

   Refer to the original guideline document for additional information on Physical Activity, including the following topics:

   • Specific roles for physical activity in obesity
   • Prevention of obesity
   • Acute weight loss
   • Long-term weight maintenance
   • Metabolic fitness with or without weight loss
   • Physical activity prescription
   • Frequency
   • Duration
   • Intensity

   Behavioral Management

   1. Identify behaviors that may lead to increased weight gain, for example: stress, emotional eating, boredom.
   2. Help patients set specific, measurable, time-limited goals to decrease calorie intake and increase physical activity as appropriate.
   3. Suggest patients weigh themselves weekly and record on a daily bases the amount and type of food/beverages consumed and physical activity completed.
   4. Provide support and encourage patients to also seek support from family, friends, and support groups in order to assist them with their eating, activity, and weight goals.

   Refer to the original guideline document for additional information on Behavioral Management, including the following topics:

   • Self-monitoring of weight, nutrition, and activity
   • Teach life skills
   • Additional behavioral modification strategies that play a key role in successful weight loss and maintenance including:
     • Stimulus control
     • Cognitive restructuring
     • Goal setting
     • Problem solving
     • Social support
     • Relapse prevention

   Medications (Pharmacologic Therapy)

   1. The short-term use of drugs (less than 3 months) has not generally been found to be effective.
   2. Pharmacotherapy should only be included in the context of a comprehensive treatment strategy.
   3. Sibutramine and Orlistat are safe for most patients when carefully monitored by a physician and may be part of a program for weight management or maintenance, which should include nutrition and physical activity when indicated.

   Refer to the original guideline document for additional information on Pharmacologic Therapy, including the following topics:

   • Safety and adverse effects (see also "Potential Harms" field in this summary)
   • Drug interactions (see also "Potential Harms" field in this summary)
   • Efficacy
   • Therapeutics
   • Patient monitoring
   • Nonprescription and natural medications (see also Appendix F in the original guideline document)

   Surgery

   1. Bariatric surgery is indicated in carefully selected patient (see "Key points" above)

   Refer to the original guideline document for additional information on Surgical Management, including the following topics:

   • Patient selection
   • Contraindications for surgery (see also the "Contraindications" field of this summary)
   • Evidence
   • Restrictive procedures, including:
     • Vertical banded gastroplasty
     • Laparoscopic adjustable gastric band
   • Malabsorptive procedures, including:
     • Biliopancreatic diversion
     • Duodenal switch
     • Roux-en-Y gastric bypass
   • Surgical procedure selection process
   • Resolution of comorbidities
   • Measurement of success and failure
   • Adolescent bariatric surgery
   • The patient process
   • Medical evaluation including obstructive sleep apnea, preoperative weight loss, and cholelithiasis
   • Postoperative care
   • Nutrition recommendations, including:
     • Gastric bypass diet progression
     • Strategies to maintain success with weight management
   • Suggested requirements for bariatric surgery facilities
   • Suggested minimum requirements for bariatric surgeons

12. Reassess Goals and Risk Factors and Counsel Regarding Weight Maintenance

    Key Points:

    • Follow-up and long-term management of weight loss is crucial.
    • The primary care physician also may serve as a community leader and a public health advocate.

    Patients need regular follow-up for obesity, which is a lifelong problem in most cases. Regular follow-up conveys the message that the condition is important to the patient, and affords the opportunity for monitoring BMI as well as evaluation and management of any of the common complications that are often associated with obesity.

    A general recommendation of visits every 3 months is based on expert opinion, and may be varied to meet the particular needs of individual patients.

Definitions:

Conclusion Grades:

Grade I: The evidence consists of results from studies of strong design for answering the question addressed. The results are both clinically important and consistent with minor exceptions at most. The results are free of any significant doubts about generalizability, bias, and flaws in research design. Studies with negative results have sufficiently large samples to have adequate statistical power.

Grade II: The evidence consists of results from studies of strong design for answering the question addressed, but there is some uncertainty attached to the conclusion because of inconsistencies among the results from the studies or because of minor doubts about generalizability, bias, research design flaws, or adequacy of sample size. Alternatively, the evidence consists solely of results from weaker designs for the question addressed, but the results have been confirmed in separate studies and are consistent with minor exceptions at most.

Grade III: The evidence consists of results from studies of strong design for answering the question addressed, but there is substantial uncertainty attached to the conclusion because of inconsistencies among the results of different studies or because of serious doubts about generalizability, bias, research design flaws, or adequacy of sample size. Alternatively, the evidence consists solely of results from a limited number of studies of weak design for answering the question addressed.

Grade Not Assignable: There is no evidence available that directly supports or refutes the conclusion.

Classes of Research Reports:

1. Primary Reports of New Data Collection:

   Class A:

   • Randomized, controlled trial

   Class B:

   • Cohort study

   Class C:

   • Non-randomized trial with concurrent or historical controls
   • Case-control study
   • Study of sensitivity and specificity of a diagnostic test
   • Population-based descriptive study

   Class D:

   • Cross-sectional study
   • Case series
   • Case report
2. Reports that Synthesize or Reflect upon Collections of Primary Reports:

   Class M:

   • Meta-analysis
   • Systematic review
   • Decision analysis
   • Cost-effectiveness analysis

   Class R:

   • Consensus statement
   • Consensus report
   • Narrative review

   Class X:

   • Medical opinion

A detailed and annotated clinical algorithm is provided in the original guideline document for Prevention and Diagnosis of Obesity.

ICSI, 8009 34th Avenue South, Suite 1200, Bloomington, MN 55425; telephone, (952) 814-7060; fax, (952) 858-9675; e-mail: icsi.info@icsi.org; Web site: www.icsi.org.

ICSI's conflict of interest policy and procedures are available for review on ICSI's website at www.icsi.org.

Electronic copies: Available from the Institute for Clinical Systems Improvement (ICSI) Web site.

Print copies: Available from ICSI, 8009 34th Avenue South, Suite 1200, Bloomington, MN 55425; telephone, (952) 814-7060; fax, (952) 858-9675; Web site: www.icsi.org; e-mail: icsi.info@icsi.org.

• Prevention and management of obesity (mature adolescents and adults). Executive summary. Bloomington (MN): Institute for Clinical Systems Improvement, 2006 Nov. 1 p. Electronic copies: Available from the Institute for Clinical Systems Improvement (ICSI) Web site.
• Body mass index-for-age percentiles. Appendix A in the original guideline document. Electronic copies: Available from the Institute for Clinical Systems Improvement (ICSI) Web site.
• Physical activity prescription. Appendix H in the original guideline document. Electronic copies: Available from the Institute for Clinical Systems Improvement (ICSI) Web site.
• ICSI pocket guidelines. April 2006 edition. Bloomington (MN): Institute for Clinical Systems Improvement, 2006. 298 p.

Print copies: Available from ICSI, 8009 34th Avenue South, Suite 1200, Bloomington, MN 55425; telephone, (952) 814-7060; fax, (952) 858-9675; Web site: www.icsi.org; e-mail: icsi.info@icsi.org.

Electronic copies: Available from the Institute for Clinical Systems Improvement (ICSI) Web site.

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