Obesity
ICD-10 E66
If your BMI puts you in the obesity range, here's what that actually means clinically, and which medications have moved to first-line in the last three years.
- 0.0%
- US adult prevalence (NHANES)
- BMI ≥0
- diagnostic threshold
- 0-10%
- weight loss = clinical benefit
- 0-22%
- GLP-1 mean weight loss in trials
What is obesity?
Obesity is a chronic disease defined by excess body fat that increases the risk of cardiovascular disease, type 2 diabetes, and other comorbidities. The American Medical Association recognized obesity as a disease in 2013. Standard threshold: BMI ≥30 (or ≥27 with a weight-related condition).
What are the symptoms of obesity?
- Excess body fat sufficient to meet the BMI threshold (≥30, or ≥27 with a weight-related comorbidity)
- Reduced physical capacity (shortness of breath on stairs, joint pain on weight-bearing activity)
- Snoring or witnessed apneic episodes (overlap with obstructive sleep apnea)
- Acanthosis nigricans — velvety dark patches at the neck/axilla (marker of insulin resistance)
- Persistent hunger and poor satiety after meals (the appetite signaling that GLP-1s target)
Who is at risk for obesity?
- Family history of obesity (genetic contribution ~40-70% per twin studies)
- Sedentary lifestyle and high ultra-processed food intake
- Sleep deprivation (under 7 hours per night)
- Certain medications: insulin, sulfonylureas, atypical antipsychotics, corticosteroids, some antidepressants
- Endocrine causes: hypothyroidism, Cushing syndrome, PCOS (in women)
- Adverse childhood experiences and chronic stress (HPA axis dysregulation)
How is obesity diagnosed?
BMI is the screening tool, calculated as weight (kg) ÷ height² (m²). BMI 25-29.9 = overweight; 30-34.9 = obese class I; 35-39.9 = class II; ≥40 = class III (severe). Waist circumference (>40" men, >35" women) supplements BMI by accounting for visceral fat distribution. Labs typically include A1C, lipid panel, liver enzymes, and TSH to evaluate metabolic comorbidities.
How is obesity treated?
First-line: lifestyle modification (calorie deficit, structured physical activity, behavioral counseling). Pharmacotherapy is indicated for BMI ≥30 or ≥27 with comorbidity. GLP-1 receptor agonists (semaglutide/Wegovy, liraglutide/Saxenda) and the dual GLP-1/GIP agonist tirzepatide (Zepbound) are now first-line drug therapy due to 14-22% mean body-weight reduction in trials. Older agents (phentermine, naltrexone-bupropion, orlistat) remain options. Bariatric surgery for BMI ≥40 or ≥35 with severe comorbidity.
Medications used for obesity
Wegovy
semaglutide · FDA 2021
Once-weekly injectable semaglutide for chronic weight management. ~15% body weight loss in trials.
Zepbound
tirzepatide · FDA 2023
Dual GLP-1/GIP agonist for weight management. ~20% body weight loss in trials — strongest weight-loss drug currently available.
Saxenda
liraglutide · FDA 2014
FDA-approved daily injectable liraglutide for chronic weight management. Older-generation GLP-1, daily dosing.
Compounded semaglutide
semaglutide (compounded)
Custom-compounded semaglutide. Cheaper than branded Wegovy. Not FDA-approved; legal landscape shifts.
Compounded tirzepatide
tirzepatide (compounded)
Custom-compounded tirzepatide. Cheaper than Zepbound/Mounjaro. Not FDA-approved.
Authority reference: www.cdc.gov
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Related topics
Sources
Primary sources cited above. FDA labeling, peer-reviewed trials, and specialty-society guidelines only.
- AHA/ACC/TOS Guideline for the Management of Overweight and Obesity in Adults · Journal of the American College of Cardiology, 2014 · PMID 24239920
- Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1) · New England Journal of Medicine, 2021 · PMID 33567185
- Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1) · New England Journal of Medicine, 2022 · PMID 35658024
- Adult Obesity Facts · Centers for Disease Control and Prevention, 2024
People also ask
Is obesity considered a disease?
Yes. The American Medical Association formally recognized obesity as a disease in 2013, and the World Health Organization classifies it as a chronic condition. This framing matters clinically (it justifies long-term treatment) and financially (it supports insurance coverage of pharmacotherapy).
How much weight loss is clinically meaningful?
5-10% body-weight reduction sustained for 6+ months produces measurable improvement in blood pressure, lipids, glucose control, and quality of life. GLP-1 trials produce 14-22% mean weight loss — well above the threshold for clinical benefit.
Do I need to fail diet and exercise before getting a GLP-1?
Clinical guidelines no longer require documented failure of lifestyle intervention before initiating pharmacotherapy if BMI criteria are met. Many insurance plans, however, do require documented prior attempts. A program with an insurance concierge handles this paperwork for you.
Will I have to take a GLP-1 forever?
Trial extension data shows roughly two-thirds of lost weight returns within 12-18 months of discontinuation. The clinical model is chronic-disease treatment, similar to managing hypertension or hyperlipidemia. Some patients move to a lower maintenance dose rather than a full stop.