Weight loss, explained with numbers, nuance, and evidence.
WeightLossOlogy helps patients and clinicians understand body composition, GLP-1 medications, protein needs, plateaus, and the limits of BMI without selling a diet ideology.
Calculators
Educational estimates only. Results should be interpreted with clinical context, medication history, pregnancy status, edema, sarcopenia risk, and body composition when available.
BMR calculator
Uses the Mifflin-St Jeor equation. Height is feet/inches; weight is pounds.
BMI calculator
BMI is useful for population screening but does not directly measure visceral fat, muscle mass, or fat distribution.
Waist-to-height ratio
Waist-to-height ratio emphasizes central adiposity. A common public-health target is to keep waist circumference less than half of height.
Relative fat mass
RFM estimates body fat percentage from height and waist. It is not a substitute for DEXA, CT, MRI, or high-quality body composition testing.
Fat mass index
FMI = fat mass in kg divided by height in meters squared. Enter body fat percent from a validated method, or use RFM as a rough estimate.
Daily protein, fiber, and water targets
These calculators give reasonable starting ranges for education and meal planning. Medical conditions may change the appropriate target.
Protein target
Fiber target
Water target
GLP-1 and incretin medication dose comparison
Educational comparison of common FDA-approved obesity medication dose schedules. Prescribing decisions, contraindications, titration speed, and dose holds require clinical judgment.
| Medication | Class | Typical starting dose | Common escalation path | Maintenance doses | Clinical notes |
|---|---|---|---|---|---|
| Wegovy® / semaglutide | GLP-1 RA | 0.25 mg weekly | 0.25 → 0.5 → 1.0 → 1.7 → 2.4 mg, usually at 4-week intervals | 1.7 or 2.4 mg weekly; higher-dose semaglutide products may be label-specific | Slow titration can reduce GI intolerance. Verify the current label before use. |
| Zepbound® / tirzepatide | GIP/GLP-1 RA | 2.5 mg weekly | 2.5 → 5 → 7.5 → 10 → 12.5 → 15 mg, generally increasing no faster than every 4 weeks | 5, 10, or 15 mg weekly | 2.5 mg is an initiation dose; dose adjustments commonly depend on tolerability and response. |
| Saxenda® / liraglutide | GLP-1 RA | 0.6 mg daily | 0.6 → 1.2 → 1.8 → 2.4 → 3.0 mg daily, often weekly steps | 3.0 mg daily | Daily injection; GI effects often guide titration pace. |
Authority-building education modules
Each section is intentionally concise for a landing page. These can later expand into full articles, videos, handouts, or patient PDFs.
Common GLP-1 side effects
Nausea, constipation, diarrhea, reflux, appetite suppression, food aversion, and injection-site reactions are common. Education should emphasize smaller meals, slower eating, hydration, constipation prevention, and appropriate dose holds when symptoms are significant.
How protein protects muscle
During weight loss, the goal is fat loss with preservation of lean mass. Adequate protein, progressive resistance training, sleep, and avoiding excessive caloric restriction are the basic protective levers.
Why BMI is not everything
BMI is fast and reproducible, but it does not distinguish fat from muscle or describe fat distribution. Waist circumference, waist-to-height ratio, metabolic markers, fitness, and body composition can provide a more complete picture.
Why waist-to-height may be better
Central adiposity tracks cardiometabolic risk better than weight alone. Waist-to-height ratio is easy to teach: measure waist consistently and compare it with height.
Understanding plateaus
Plateaus are expected. They may reflect adaptive reductions in energy expenditure, improved appetite control leading to less visible change, inconsistent tracking, medication dose limits, fluid shifts, or decreased spontaneous movement.
Clinically significant weight loss
Even 5% weight loss can improve glycemia, triglycerides, blood pressure, and liver fat in many patients. Greater losses of 10–15% or more often produce larger changes in obstructive sleep apnea, mobility, steatotic liver disease, and diabetes remission probability.
Muscle, bone, and medication-assisted loss
Faster weight loss can increase lean-mass loss risk. Older adults, postmenopausal women, and patients with low baseline strength benefit from early resistance training, protein planning, and fall-risk awareness.
Stopping GLP-1 therapy
Many patients regain weight after stopping anti-obesity pharmacotherapy. The transition plan should address appetite return, nutrition structure, resistance training, monitoring, sleep, and follow-up.
Measurement quality matters
Use the same scale conditions, the same waist landmark, and consistent tape tension. A tension-regulated tape can reduce measurement noise for waist tracking.
Landmark studies and evidence links
Starting points for patients, clinicians, and writers building an evidence-based obesity education library.
Look AHEAD
Long-term intensive lifestyle intervention in adults with type 2 diabetes and overweight/obesity; important for understanding durability, fitness, weight loss, and cardiovascular outcome complexity.
Open NEJM study →Framingham Heart Study
A foundational cohort for cardiovascular risk epidemiology and risk-factor thinking, relevant to obesity, blood pressure, lipids, and long-term risk modeling.
Open Framingham site →STEP 1 — semaglutide 2.4 mg
Major semaglutide obesity trial demonstrating substantial body-weight reduction with once-weekly semaglutide plus lifestyle intervention.
Open NEJM study →SURMOUNT-1 — tirzepatide
Major tirzepatide obesity trial demonstrating substantial and sustained body-weight reduction at 72 weeks.
Open NEJM study →SELECT — semaglutide CV outcomes
Cardiovascular outcomes trial in adults with overweight/obesity and established cardiovascular disease without diabetes.
Open NEJM study →SURMOUNT-5 — tirzepatide vs semaglutide
Head-to-head trial comparing tirzepatide with semaglutide for obesity outcomes.
Open NEJM study →