Obesity

1. In patients who appear to be obese, make the diagnosis of obesity using a clear definition (i.e., currently body mass index) and inform them of the diagnosis.

2. In all obese patients, assess for treatable co-morbidities such as hypertension, diabetes, coronary artery disease, sleep apnea, and osteoarthritis, as these are more likely to be present.

3. In patients diagnosed with obesity who have confirmed normal thyroid function, avoid repeated thyroid-stimulating hormone testing.

4. In obese patients, inquire about the effect of obesity on the patient’s personal and social life to better understand its impact on the patient.

5. In a patient diagnosed with obesity, establish the patient’s readiness to make changes necessary to lose weight, as advice will differ, and reassess this readiness periodically.

6. Advise the obese patient seeking treatment that effective management will require appropriate diet, adequate exercise,and support (independent of any medical or surgical treatment), and facilitate the patient’s access to these as needed and as possible.

7. As part of preventing childhood obesity, advise parents of healthy activity levels for their children.

8. In managing childhood obesity, challenge parents to make appropriate family-wide changes in diet and exercise, and to avoid counterproductive interventions (e.g., berating or singling out the obese child).

General Overview

• Adult BMI

  • ≥25 Overweight

  • ≥ 30 Obese class 1

  • ≥ 35 Obese class 2

  • ≥ 40 Obese class 3

• Overestimated/underestimated depending on muscle:fat distribution

  • eg. South Asian criteria for BMI

    • ≥23 Overweight

    • ≥25 Obese

• Additional measures such as waist circumference, waist-to-hip ratio and waist-to-height-ratio, if BMI>25 (no clear evidence)

• Causes and Co-morbidities 

  • Metabolic: 

    • Hypothyroidism, Cushing's, Polycystic ovarian syndrome, Male hypogonadism

    • Diabetes mellitus type II, insulin resistance, metabolic syndrome, dyslipidemia, metabolic-associated steatotic liver disease

  • Mechanical: Obstructive sleep apnea (OSA), osteoarthritis, reflux

  • Medications: Insulin, sulfonylureas, antipsychotics

  • Monetary: Education, income, disability, insurance

  • Mental health: Depression, anxiety, insomnia

  • Cardiovascular: Hypertension, coronary artery disease

Investigation

• History and physical exam rule out secondary causes

  • Vitals (Blood pressure)

  • Weight, height, waist circumference

  • Impact personal and social life 

  • Rule out depression, eating disorder

• Labs

  • HbA1c or fasting blood glucose

  • Lipid profile

  • Consider Thyroid (avoid repeating if confirmed normal)

Management

5A's of Obesity Management

• Ask (Readiness to change):

  • Is it alright if we discuss your weight?

• Assess

  • Identify root causes, complications, related comorbidities, and barriers (physical, mental, psychosocial) to obesity treatment

  • Physical exam: Height, weight, waist circumference, blood pressure

  • Labs: Lipid panel, HbA1c

• Advice

  • Individualized plan to address root cause

  • Behavioural changes: 

    • Nutrition

      • Individualized medical nutrition therapy by a registered dietition if available

      • Longterm sustainable healthy eating pattern with a balance of macronutrients and a positive relationship with food

    • Physical activity

      • 30-60 minutes of moderate to vigorous intesnity most days of the week

  • Adjunctive therapies may include dietician, personal trainer, psychology (Cognitive behavioural therapy), psychiatry, endocrinologist/obesity specialist, pharmacology and surgical intervention

  • BMI ≥30  after lifestyle/behavioural changes have failed

    • Structured behavioural interventions (weight loss program)

    • Pharmacotherapy (BMI>27 with comorbidities or BMI>30)

      • GLP1-RA

        • Semaglutide (Ozempic) 2.4mg SC Weekly 

        • Tirzepatide (Mounjaro) 5mg, 10mg, or 15mg SC weekly

        • Liraglutide 3mg SC Daily 

        • Adverse effects: Nausea, vomiting, indigestion, fatigue

        • Contraindication: personal or family history of medullary thyroid cancer and MEN II; hx of hypersensitivity to the drug; history of pancreatitis; pregnancy

      • Bupropion and naltrexone (Contrave) 16/180mg PO BID

      • Orlistat 120mg PO daily-TID

        • Stop medication if weight loss <5% at 3 months

        • No effect on mortality

        • Adverse effects: Bloating, steatorrhea, fecal incontinence

          • Lack of longterm safety data

          • Supplement with multivitamin 2h before or after medication

      • Consider GLP-1/SGLT2 for weight loss in diabetes (in addition to Metformin)

    • BMI ≥ 40 or ≥ 35 with comorbidity (OA, OSA), consider Bariatric Surgery to help with weight loss and reduce prevalence of chronic disease (eg. DM, HTN, DLP, MSK pain - RR decrease by 25%)

• Agree:

  • SMART goals focused mainly on the value the person derives from health-based interventions

• Assist: 

  • Provide education and resources

  • Continued follow-up and reassessments, and encouragement

Childhood

• • Normal - BMI < 85th percentile

  • Overweight- BMI > 85th percentile

  • Obese > 97th percentile

    • Severe Obesity >99th percentile

Management

• • Structured behavioural interventions

  • Family-wide changes in diet and activity (family-oriented behaviour therapy)

    • Avoid counterproductive interventions (e.g., berating or singling out the obese child)

    • Encourage positive reinforcement

  • Diet

    • Family meals

    • Healthy snacking

    • Decreased sugar consumption (juices, drinks)

    • Decrease portion size

    • Increase vegetables

  • Activity (WHO recommends 60 minutes moderate-vigorous daily)

    • Focus on fun/recreational activity

    • Limit screen time

    • Limit motorized transport

    • Limit time spent indoors

    • Limit sitting (eg. stroller)

  • Sleep

Lasted edited 2025-08-01
A. Al Zatam, K. Chan