Obesity

Kimberly Schuster

Background 

  • 42% of US adults are obese. 74% of adults are overweight or obese.

Evaluation 

  • USPTF: Pts with BMI >30 should be offered or referred to intensive, multicomponent behavioral interventions. 
  • Screen for co-morbidities: HTN (BP), HLD (lipid panel), DM (A1c), MASLD (LFTs), OSA (polysomnography), consider TSH if other symptoms of thyroid dysfunction. 
  • Assess medication list for weight-promoting agents (antipsychotics, insulin, sulfonylureas, steroids, TCAs, gabapentin).

Lifestyle Interventions 

  • Diet: Total calorie restriction is most effective. Encourage sustainable patterns (Mediterranean, DASH). ~500 kcal/day deficit → ~0.5 kg/week loss. Limit high-caloric beverages and ultraprocessed foods. 
  • Exercise: Goal ≥150 min/week moderate-intensity aerobic + resistance training. 
  • Behavioral Support: Food logs, MyPlate, apps (MyFitnessPal, Noom). EPIC dot phrases: .NHFOODHEALTHYPLATE, .NHOBESITYYMCA. 
  • Goals: Even 3–5% weight loss produces meaningful improvements in glycemic control, BP, and lipids. Target 5–10%. Frame as chronic disease requiring long-term follow-up.

Pharmacotherapy

  • Indications: BMI ≥ 30 OR BMI ≥27 with weight-related comorbidity (HTN, T2DM, dyslipidemia, OSA, MASLD, CVD). Offer along lifestyle changes. 
  • First-line (preferred): GLP-1 receptor agonists and dual GIP/GLP-1 receptor agonists.

Agent

Starting Dose

Target Dose

Avg. Weight Loss

Key Points
Semaglutide
(Wegovy) 		0.25 mg SQ weekly × 4 wks, then titrate monthly

OR

1.5 mg PO daily × 4 wks, then titrate monthly 		2.4 mg SQ weekly

OR

25 mg PO daily 		~15-17% First-line preferred
FDA-approved for secondary CV prevention; also approved for MASH
Oral option available
Tirzepatide
(Zepbound) 		2.5 mg SQ weekly × 4 wks, then titrate monthly 15 mg SQ weekly ~20-21% Highest efficacy
Dual GLP-1/GIP agonist
FDA-approved for OSA in obesity
Superior to semaglutide in head-to-head (NEJM 2025)
Liraglutide
(Saxenda) 		0.6 mg SQ daily, titrate weekly 3.0 mg SQ daily ~7-8% Daily injection; less effective; alternative if weekly agents not tolerated/available
Phentermine-topiramate
(Qsymia) 		Per titration schedule Full strength cap daily ~9-10% Use if GLP-1 RAs not tolerated/accessible
CI: glaucoma, hyperthyroidism, MAOIs, pregnancy
Naltrexone-bupropion
(Contrave) 		Per titration schedule 32/360 mg daily ~5-6% Use if GLP-1 RAs not tolerated/accessible
CI: seizure disorder, opioid use, uncontrolled HTN

GLP-1 RA Initiation/Counseling

Pre-Initiation 

  • Contraindications: personal/family history of medullary thyroid carcinoma or MEN2; known hypersensitivity, pancreatitis 
  • Baseline: weight, A1c, lipid panel, renal function 
  • If on insulin: dose reduce 10-20%. Discontinue sulfonylureas. 

Patient Counseling Points 

  • Chronic therapy (stopping results in 50-67% weight gain within 1 year) 
  • Titration (start low, go slow) with monthly dose increases to minimize GI side effects. Effective dose may be less than maximum. 
  • Injection technique: subQ in abdomen, thigh, upper arm; rotate sites. 
  • Diet Modifications: smaller meals, eat slowly, emphasize protein and resistance training to preserve lean mass - Storage: refrigerate unused pens (in use tolerate room temp for 4-6 weeks) 

Managing Side Effects 

  • Side effects are typically dose dependent, GI-related, and improve over time 
  • Nausea/Emesis (33-44%): smaller meals, avoid high-fat foods; Zofran prn 
  • Dyspepsia: H2 blocker or PPI 
  • Constipation: fiber, hydration, miralax/psyllium 
  • If intolerable: decrease to previously tolerated dose; slow titration every 6-8 weeks 

Complications 

  • Pancreatitis: discontinue if suspected; do not restart 
  • Gallbladder disease: increased risk of cholelithiasis 
  • Pregnancy: discontinue ≥2 months before planned pregnancy 

Referrals

  • Medical Weight Loss Clinic: BMI ≥ 30 or ≥27 with comorbidity 
  • VA Patients: MOVE program (in-person or telehealth) 
  • Bariatric Surgery: BMI ≥ 40 or ≥ 35 with comorbidity
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