The recommendations that follow are those from the guideline’s executive summary; detailed recommendations can be found in the original guideline document. Each recommendation is rated based on the level of the evidence and the grades of recommendation. Definitions of the grades of the recommendations (A, B, C, Good Practice Points [GPP]) and level of the evidence (Level I-Level IV) are presented at the end of the Major Recommendations field.
Diagnosis & Clinical Evaluation
B - Body mass index (BMI) is the recommended index to define overweight and obesity. It is minimally correlated with height and highly correlated with body fat percentage and levels of disease risk of comorbidities. Body weight alone can be used to follow weight loss and to determine efficacy of therapy. (Grade B, Level III)
C - Current World Health Organization (WHO) and international guidelines recommend BMI cutoffs of 25 and 30 kg/m2 to define overweight and obesity respectively. Based on body fat equivalence and comorbid disease risk, BMIs of 23 and 27.5 kg/m2 respectively have been recommended as cut-off points for public health action in Asians. (Grade C, Level IV)
Nota bene (N.B.) BMI cut-off points are currently being reviewed in the light of new data.
B - Waist circumference is the most practical anthropometric measurement for assessing a patient’s abdominal fat content before and during weight loss treatment. Gender-specific waist circumference cut-offs should be used in conjunction with BMI to identify increased disease risk. (Grade B, Level III)
C - Current international guidelines recommend waist circumference cut-offs of 102 and 88 cm to define excess risk in males and females respectively. Based on an Asian-Pacific consensus and our National Health Survey and comorbid disease risk, cut-offs of 90 and 80 cm respectively are probably more appropriate for Asians. (Grade C, Level IV)
B - Historically, weight-for-height charts have been used to classify weight status in children. BMI-for-age and gender charts are recommended for use in children. (Grade B, Level III)
GPP - In clinical evaluation of patients, practitioners should consider and exclude predisposing factors for and secondary causes of obesity. (GPP)
C - Overweight and obese adults should be screened for comorbid conditions and should be stratified according to their health risks, in particular for cardiovascular disease, prior to the commencement of treatment. (Grade C, Level IV)
Overview of Weight Management
C - Patient motivation is an important prerequisite of weight loss management and should be relatively high before initiating therapy. Proper evaluation of issues related to motivation should be undertaken. (Grade C, Level IV)
C - It is important to set realistic goals for weight loss and provide sound advice on lifestyle modification. Modest weight loss (e.g., 10% body weight over 6 months) is more realistic and attainable than aiming for weight reduction to ideal body weight and does result in a reduction in obesity morbidity. (Grade C, Level IV)
C - A multifaceted or multidisciplinary strategy should be utilized to achieve and maintain weight loss. Depending on patient response, this could be adequately achieved at the primary health care level or tertiary level. (Grade C, Level IV)
Lifestyle Modification
A - The combination of dietary caloric restriction, physical activity, and behavioural modification results in greater and more sustained weight loss than the individual modalities. (Grade A, Level Ib)
A - The most important dietary component of weight loss and maintenance is a decrease in caloric intake (National Heart, Lung, and Blood Institute (NHLBI) Obesity Education Initiative, 1998). Typically, a 500 to 1,000 kcal per day reduction produces the recommended 0.5 to 1 kg per week weight loss (NHLBI Obesity Education Initiative, 1998). In the absence of physical activity, a diet that contains approximately 1,400 to 1,500 kcal/day, regardless of macronutrient content, results in weight loss (NHLBI Obesity Education Initiative, 1998; Freedman, King, & Kennedy, 2001; St Jeor et al., 2001; Hadjuk, Roberts, & Saltzman, 2001; Pirozzo et al., 2002; Anderson, Konz, & Jenkins, 2000; Bravata et al., 2003; Klem et al., 1997). Sustained dietary modification is necessary to maintain weight loss. (Grade A, Level Ib)
C - Diets containing different proportions of the major macronutrients, such as moderate-fat balanced nutrient-reduction diets, high-fat low carbohydrate diets, and low- or very-low-fat high-carbohydrate diets have all been shown to reduce weight. Weight loss appears to be more associated with reduced caloric intake and increased diet duration, rather than the macronutrient content per se. A diet moderately restricted in total fat, moderate to high in complex carbohydrates, and moderate in protein is the most widely recommended diet. (Grade C, Level IV)
C - The distribution of food intake should be as even as possible throughout the day, and meals should not be skipped as a weight control method. Meals should be adequately sized so that snacks are not needed between meals (The Asia-Pacific Perspective, 2000). (Grade C, Level IV)
A - Low-calorie (LCD) and very low-calorie diets (VLCD) may be useful shorter term adjuncts (up to 6 months) for weight loss, but sustained modification of food intake is necessary to maintain weight loss. The use of these diets as part of a meal replacement strategy appears useful. The combination of a controlled energy diet (LCD or VLCD), increased physical activity, and behaviour therapy appears to provide the most successful outcome for weight loss and maintenance. (Grade A, Level Ib)
A - Current physical activity contributes to weight loss, reduces cardiovascular risk factors (e.g., hypertension and diabetes mellitus) and the risk for coronary heart disease, increases cardiorespiratory fitness independent of weight loss, and decreases body and abdominal fat. (Grade A, Level Ib)
C - The current recommendation of moderate-intensity physical activity for 30 min, 3 to 5 days per week, is largely aimed at reducing cardiovascular disease and overall mortality. (Grade C, Level IV)
C - To prevent unhealthy weight gain, moderate-intensity physical activity for 45 to 60 min on most days or every day has been recommended. Preventing weight gain after substantial weight loss probably requires about 60 to 90 minutes per day. Starting at low-to-moderate physical activity for 30 to 45 min, 3 to 5 days per week, the intensity, duration, and frequency should be increased gradually. (Grade C, Level IV)
A - A program of diet plus nonstructured, moderate-intensity lifestyle activity appeared as effective as diet plus structured aerobic activity for reducing weight in obese women. Any increase in daily physical activity is likely to have some benefit in obese women. (Grade A, Level Ib)
B - The presence of depression and binge eating disorders in obese patients must be evaluated for, with appropriate referral for psychiatric treatment (Stunkard & Allison, 2003). (Grade B, Level IIa)
A - Weight loss programs incorporating cognitive behavioural interventions are helpful in achieving weight loss and weight maintenance in the range of up to 10% for between 1 to 5 years of follow-up. (Grade A, Level Ib)
A - It is recommended that subjects continue with up to 12 months of the weight maintenance program combining behaviour therapy, a low calorie diet, and exercise, after the initial weight loss treatment. (Grade A, Level Ib)
Medical Treatment
C - As obesity is a chronic condition that requires lifelong management, pharmacotherapy should be adjunct to an individual’s long-term obesity management strategy (NHLBI Obesity Initiative, 1998). (Grade C, Level IV)
A - Drug therapy may be effective if given without lifestyle modification (Wadden et al., 2001; Tong et al., 2002) but is most effective when combined with diet, physical activity, and behaviour modification (Wadden et al., 2001). (Grade A, Level Ib)
C - Drug therapy should be considered when BMI >30 kg/m2 or when BMI is 27-29.9 kg/m2 in patients with comorbidities or complications of obesity such as hypertension, type 2 diabetes mellitus, hyperlipidemia, coronary artery disease, and sleep apnea (NHLBI Obesity Initiative, 1998). Commensurate BMI thresholds for action among Asians may be 27.5 and 25 to 27.4 kg/m2 respectively ("Appropriate body-mass index," 2004). (Grade C, Level IV)
N.B. BMI cut-off points are currently being reviewed in the light of new data.
A - The drugs with the widest efficacy and safety data are orlistat (up to 4 years) and sibutramine (up to 2 years). Other drugs which appear relatively safe and effective for 6 to 12 month therapy include phentermine and mazindol. There is little data on the effectiveness of combining antiobesity agents. Metformin is the drug of choice in obese diabetics and has been effectively combined with either sibutramine or orlistat for 1 year. (Grade A, Level Ib)
Bariatric Surgery
A - Bariatric surgery is the most effective method to reduce weight and maintain weight loss in the severely or morbidly obese. (Clegg et al., 2002) Grade A, Level Ib)
C - Because surgery has significant technical issues, complications, and cost, and requires extensive pre- and perioperative preparation, it is usually considered in those with more severe obesity who have failed to control weight by other means ("Gastrointestinal surgery for sever obesity," 1992; "Guidelines for laparoscopic surgery," 2001; Brolin, 2002), and who remain at high risk of medical comorbidities. Postoperative lifestyle modifications, as well as follow-up for complications of surgery, are life-long. (Grade C, Level IV)
B - Indications for considering bariatric surgery are (NHLBI Obesity Education Initiative, 1998; Clegg et al., 2002; "Gastrointestinal surgery for severe obesity," 1992; "Guidelines for laparoscopic surgery," 2001; Brolin, 2002):
- Extreme or morbid obesity (BMI >40 kg/m2) or severe obesity (BMI >35 kg/m2) with medical comorbidities or complications of obesity. Commensurate BMI thresholds for action among Asians may be 37.5 and 32.5 kg/m2 respectively ("Appropriate body-mass index," 2004).
- Failure of significant nonsurgical attempts at weight reduction. (Grade B, Level III)
Weight Loss Maintenance
B - Common behavioral strategies which may enhance successful long-term weight loss maintenance include eating a calorie-restricted, low-to-moderate fat diet, frequent self-monitoring of body weight, recording food intake and physical activity, and maintaining high levels of regular physical activity. (Grade B, Level III)
Obesity in Childhood and Adolescence
C - A full clinical evaluation and possible treatment should be considered in children with a BMI >95th percentile or a BMI >85th percentile and complications of obesity. Alternatively, BMIs-for-age and gender equivalent to adult WHO BMI cut-offs for obese and overweight (at >30.0 or >25.0 kg/m2) respectively can be used as thresholds, although BMI cut-offs for action among Asians of 27.5 and 23.0 kg/m2 respectively may eventually be used. (Grade C, Level IV)
N.B. BMI cut-off points are currently being reviewed in the light of new data.
C - In children, less restrictive diets should be used, rather than diets consisting of drastically altered portions of various nutrients, very low calorie diets, or protein sparing modified fast regimens. (Grade B, Level III)
B - Appropriately increased physical activity is recommended. Younger children generally need age-appropriate creative activities with generous periods of free play. Weight bearing activities are recommended for overweight children, non-weight bearing activities for obese children, and preferably supervised activities for severely obese children. In the older obese preadolescent and adolescent, decreased time on sedentary pursuits and increased activity such as a moderate intensity, progressive exercise program with increasing levels of obesity are recommended. (Grade B, Level III)
B - Behaviour-treatment programs have shown consistent success in weight loss (Epstein, Roemmich, & Raynor, 2001). (Grade B, Level IIa)
B - Interventions for obesity in children should be directed at both the parents and the child, rather than the child alone. (Grade B, Level III)
C - There are no data on the long term efficacy and safety of medication in childhood and adolescent obesity. (Grade C, Level IV)
B - Bariatric surgery cannot be recommended for most adolescents, but only for those at the highest risk of mortality from obesity, and with both patient and parental understanding of the consequences of surgery (Sugerman et al., 2003). (Grade B, Level III)
Grades of Recommendations
Grade A (evidence levels Ia, Ib): Requires at least one randomised controlled trial as part of the body of literature of overall good quality and consistency addressing the specific recommendation.
Grade B (evidence levels IIa, IIb, III): Requires availability of well conducted clinical studies but no randomised clinical trials on the topic of recommendation.
Grade C (evidence level IV): Requires evidence obtained from expert committee reports or opinions and/or clinical experiences of respected authorities. Indicates absence of directly applicable clinical studies of good quality.
GPP (good practice points): Recommended best practice based on the clinical experience of the guideline development group.
Levels of Evidence
Level Ia: Evidence obtained from meta-analysis of randomised controlled trials
Level Ib: Evidence obtained from at least one randomised controlled trial
Level IIa: Evidence obtained from at least one well-designed controlled study without randomisation
Level IIb: Evidence obtained from at least one other type of well-designed quasi-experimental study
Level III: Evidence obtained from well-designed nonexperimental descriptive studies, such as comparative studies, correlation studies and case studies
Level IV: Evidence obtained from expert committee reports or opinions and/or clinical experiences of respected authorities
