ABOM Oral Medicine cheat sheet

BMI (kg/m²) classifications: underweight <18.5; normal 18.5–24.9; overweight 25–29.9; class I obesity 30–34.9; class II 35–39.9; class III ≥40.

Waist circumference thresholds for increased cardiometabolic risk: >102 cm (40 in) in men and >88 cm (35 in) in women; lower thresholds (>90 cm men, >80 cm women) for Asian populations.

Obesity is a chronic, relapsing, progressive disease; diagnosis requires a documented BMI ≥30 or BMI ≥27 with at least one weight-related comorbidity.

Weight-related comorbidities include type 2 diabetes, hypertension, dyslipidemia, obstructive sleep apnea, MASLD (metabolic dysfunction-associated steatotic liver disease), osteoarthritis, and GERD.

A 5–10% weight loss improves glycemia, blood pressure, and lipids; ≥10% may improve sleep apnea and steatohepatitis; ≥15% may induce type 2 diabetes remission.

Use the Edmonton Obesity Staging System (EOSS) stages 0–4 to assess health status and functional impact independent of BMI.

Screen for secondary causes when indicated: hypothyroidism, Cushing syndrome, hypothalamic injury, and medications (glucocorticoids, antipsychotics, some antidepressants, insulin, sulfonylureas).

Initial evaluation includes BMI, waist circumference, blood pressure, fasting glucose or HbA1c, lipid panel, liver enzymes, and assessment of sleep apnea symptoms.

Energy balance: 1 kg body fat ≈ 7,700 kcal; a 500–750 kcal/day deficit typically yields 0.5–0.75 kg/week weight loss.

Treatment intensity should match BMI and comorbidity: lifestyle alone for BMI 25–29.9; add pharmacotherapy for BMI ≥30 or ≥27 with comorbidity; consider bariatric surgery for BMI ≥40 or ≥35 with comorbidity (≥30 with type 2 diabetes in some guidelines).

Anti-obesity medications: phentermine/topiramate ER, naltrexone/bupropion ER, orlistat, liraglutide 3.0 mg, semaglutide 2.4 mg, and tirzepatide; set realistic expectations of 5–15% weight loss depending on agent.

Avoid anti-obesity pharmacotherapy in pregnancy, within 6 months of a cardiovascular event (for sympathomimetics), and in uncontrolled hypertension or history of eating disorders where contraindicated.

Bariatric surgery types: sleeve gastrectomy, Roux-en-Y gastric bypass, adjustable gastric band, and biliopancreatic diversion with duodenal switch; expected excess weight loss varies by procedure (band ~40–50%, sleeve ~50–60%, bypass ~60–70%).

Post-bariatric nutritional monitoring: vitamin B12, iron, calcium/vitamin D, folate, and thiamine; lifelong micronutrient supplementation is typically required after bypass.

Dumping syndrome after gastric bypass: early dumping (10–30 min) from rapid gastric emptying; late dumping (1–3 h) from reactive hypoglycemia; manage with small, low-sugar, high-protein meals.

Physical activity: ≥150 min/week moderate-intensity aerobic activity plus 2–3 resistance sessions weekly to preserve lean mass during weight loss.

Weight regain after lifestyle or pharmacologic intervention is common; long-term follow-up and intensification are part of chronic disease management.

Obesity increases risk for type 2 diabetes, hypertension, dyslipidemia, OSA, MASLD, osteoarthritis, GERD, certain cancers, and depression; screen and treat comorbidities concurrently.