What are the guidelines for the treatment of obesity?

Guidelines for the Treatment of Obesity

Obesity must be treated as a chronic disease requiring a multidisciplinary team approach, with comprehensive lifestyle intervention for 6-12 months as the essential foundation, followed by pharmacotherapy for BMI ≥30 kg/m² (or ≥27 kg/m² with complications) when lifestyle measures fail, and bariatric surgery reserved for BMI ≥35 kg/m² with complications or BMI ≥40 kg/m² when all non-surgical interventions have been unsuccessful. 1, 2

Diagnosis and Risk Stratification

Use BMI as the primary diagnostic measure: BMI ≥30 kg/m² indicates obesity and BMI 25-29.9 kg/m² indicates overweight, both associated with increased cardiovascular disease risk and mortality. 1, 2

Measure waist circumference as a mandatory additional assessment to evaluate abdominal adiposity and risk of obesity-related complications. Cut points: ≥88 cm for women and ≥102 cm for men in Western populations. 1, 2

Conduct comprehensive clinical assessment to identify weight-related complications including type 2 diabetes, hypertension, dyslipidemia, sleep apnea, cardiovascular disease, and non-alcoholic fatty liver disease. 2

First-Line Treatment: Comprehensive Lifestyle Intervention (6-12 Months)

All patients with obesity require a multifactorial lifestyle program lasting at least 6-12 months before considering other interventions. This is non-negotiable and forms the foundation of all obesity treatment. 1, 2

Dietary Intervention

Reduce caloric intake by at least 500 kcal/day from baseline, ensuring adequate protein, vitamins, and minerals. 1, 2

Macronutrient distribution should be: approximately 55% carbohydrates, 10% protein, and 30% fat (with ≤10% from saturated fats). 1

Very low calorie diets (≤800 kcal/day) should not be used routinely but may be considered only for specific medical conditions requiring rapid weight loss (e.g., severe weight-related complications), and always require medical supervision. 1

Physical Activity

Prescribe at least 30 minutes of moderate-intensity endurance exercise five or more days per week (minimum 150 minutes/week), combined with strength training. 1, 2

For patients with BMI >35 kg/m², select activities that minimize musculoskeletal stress (e.g., swimming, cycling, walking on level surfaces). 1

Mandate reduction in sedentary behaviors including television watching and computer use. 1

Behavioral Modification

Implement behavioral therapy strategies including self-monitoring of food intake and physical activity, stimulus control, mindful eating, and stress management techniques. 2

Provide regular contact (in-person or telephone) throughout the intervention period to support adherence and address barriers. 1

Second-Line Treatment: Pharmacotherapy

Initiate pharmacological weight reduction only as an adjunct to ongoing lifestyle interventions in the following scenarios: 1, 2

• BMI ≥30 kg/m² without complications
• BMI ≥27 kg/m² with weight-related complications (diabetes, hypertension, dyslipidemia)
• BMI ≥28 kg/m² with additional cardiovascular risk factors

Continue pharmacotherapy only if the patient achieves:

• At least 5% weight loss during the first 3 months, OR
• At least 2 kg weight loss during the first 4 weeks of treatment 1

Discontinue medication if these thresholds are not met, as continued use is unlikely to provide meaningful benefit. 1

Available FDA-approved options include: phentermine (short-term use only for BMI ≥30 kg/m² or ≥27 kg/m² with risk factors), orlistat, naltrexone/bupropion, liraglutide, and other GLP-1 receptor agonists. 2, 3

Avoid off-label use of medications solely for weight loss. 1

Third-Line Treatment: Bariatric Surgery

Offer bariatric surgery when all non-surgical interventions have failed in the following patient groups: 1, 2

• BMI ≥40 kg/m² (regardless of complications)
• BMI ≥35 kg/m² with weight-related complications (diabetes, hypertension, sleep apnea, severe joint disease)

For BMI >50 kg/m², bariatric surgery is a treatment option whether or not conservative interventions have been attempted previously. 1

Special consideration: Bariatric surgery may be considered for patients with diabetes and BMI 30-34.9 kg/m², though evidence is limited and long-term data are lacking. 1

The decision to proceed with surgery must follow comprehensive multidisciplinary assessment by a team experienced in obesity management and bariatric surgery. 1

Higher age is not a contraindication, though individual risk-benefit assessment is required for patients ≥65 years. 1

Post-Surgical Care

Provide mandatory long-term multidisciplinary follow-up for at least 2 years (and often lifelong), including: 1

• Dietetic monitoring and individualized nutritional supplementation
• Micronutrient monitoring and replacement
• Psychological support
• At least one annual appointment with a physician experienced in obesity and bariatric surgery

Long-Term Weight Maintenance

After achieving weight loss, implement indefinite maintenance strategies including: 1, 2

• Continued healthy, low-calorie balanced diet
• Sustained physical activity (≥150 minutes/week moderate-intensity exercise)
• Ongoing behavioral support with regular contact (in-person or telephone) for at least 1 year
• Consider chronic pharmacotherapy for weight maintenance when benefits outweigh risks

Set realistic expectations: Target 5-15% weight loss over 6 months, recognizing that weight maintenance is more challenging than initial weight loss. 2, 4

Critical Pitfalls to Avoid

Do not treat obesity as an acute, self-limited condition. It is a chronic disease requiring lifelong management. 1, 2

Do not discontinue support after initial weight loss without establishing a comprehensive maintenance plan, as weight regain is common. 1, 5, 2

Do not use pharmacotherapy or consider surgery without first implementing comprehensive lifestyle intervention for an adequate duration (6-12 months). 1, 2

Do not use BMI alone for diagnosis without confirming excess adiposity through waist circumference or other anthropometric measures. 1, 2, 6

Use respectful, non-stigmatizing language in all patient interactions, as weight bias is a major barrier to effective treatment. 2, 6