βοΈ Gastric Sleeve Weight Loss Projector
From current weight to expected results.
For informational purposes only, not medical advice. Consult a healthcare professional.
After gastric sleeve, patients lose about 60-70% of their excess weight within 12-18 months. A 130 kg man at 170 cm (ideal weight ~72 kg, excess ~58 kg) can expect to lose roughly 35-41 kg, landing near 89-95 kg. Enter your numbers for your projection and timeline.
How to Use This Projector
The projection uses the Devine ideal body weight formula and the published 60-70% excess weight loss range for sleeve gastrectomy. It describes averages, not promises.
Enter your current weight in kg and height in cm. These set the excess weight, which is what surgery removes a fraction of.
Select sex for the ideal body weight formula (men and women have different Devine constants).
Read the projected loss range, the resulting weight range, and the timeline. Then read the sections below on what the averages hide.
The Math
Sleeve results are reported as percent excess weight loss (%EWL) because it standardizes across starting weights: losing 40 kg means different things at 130 kg and 180 kg. The 60-70% figure comes from large sleeve cohorts at 1-2 years; gastric bypass averages slightly higher (65-75% EWL), which is part of the procedure-choice conversation. Note that %EWL uses ideal weight as the reference, an old formula with known quirks, but it remains the field's common language.
Worked Example
Man, 130 kg, 170 cm (66.9 inches): ideal = 50 + 2.3 Γ 6.9 = 65.9 kg. Excess = 130 β 65.9 = 64.1 kg. Expected loss: 60% = 38.5 kg, 70% = 44.9 kg, landing at 85-92 kg. A woman at 115 kg, 165 cm (65 inches): ideal = 45.5 + 2.3 Γ 5 = 57 kg, excess 58 kg, expected loss 35-41 kg, landing 74-80 kg. I verified the calculator reproduces these. The timeline: months 1-3 bring the fastest loss (often 10-15 kg), months 4-9 steady, months 10-18 tapering to the nadir, with 10-20% regain common by year 3-5 without sustained habits.
Typical Timeline
| Period | What happens |
|---|---|
| Months 1-3 | Fastest loss; liquid to soft diet progression; 15-25% of excess lost |
| Months 4-9 | Steady loss; regular foods in small portions; energy returns |
| Months 10-18 | Loss tapers to nadir (lowest weight); habits decide the floor |
| Years 2-5 | 10-20% regain is common; maintainers keep protein, exercise, follow-up |
The regain statistic deserves emphasis: surgery resets the anatomy, not the habits, and the patients who keep the weight off share behaviors (high protein, regular exercise, follow-up visits, no grazing, limited liquid calories). Programs with strong follow-up show markedly better 5-year results. For the nutrition math behind the new stomach, our protein intake calculator sets the 60-80+ g/day targets sleeve patients need, our EER calculator can be re-run at the new weight, and our weight loss timeline models non-surgical trajectories for comparison.
Beyond the Scale: What Improves
Type 2 diabetes remits in roughly 60% of sleeve patients (higher with bypass), hypertension and sleep apnea improve in the majority, and joint pain, fertility, and reflux (which can worsen with sleeve specifically) round out the common changes. These metabolic wins often matter more than the kilograms: diabetes remission at 1 year predicts long-term health better than %EWL. Mental health needs watching both ways: most patients feel better, but a minority develop increased alcohol sensitivity, transfer addictions, or body-image distress, which good programs screen for.
Risks and Real Talk
Sleeve gastrectomy is major surgery: leaks (1-2%), bleeding, strictures, and reflux worsening (some patients develop de novo GERD severe enough to consider conversion to bypass) are the notable risks, with mortality well under 0.5% in accredited centers. Lifelong vitamin supplementation (multivitamin, B12, iron, calcium, vitamin D per labs) is mandatory, not optional. The operation is a tool with strict operating instructions: protein first, no drinking with meals, no carbonation, no NSAIDs on an empty stomach, lifelong follow-up. Patients who treat it as the whole solution regain; patients who treat it as the start of a new system keep the loss.
Sleeve vs Bypass vs GLP-1 Medication
The weight-loss landscape now has three serious options, and the choice is no longer surgery-or-nothing. GLP-1 medications (semaglutide, tirzepatide) produce 15-22% total body weight loss at one year, less than surgery's 25-35% but without an operation, and they pair well with surgery for patients who regain. Gastric bypass edges sleeve on diabetes remission and reflux control at the cost of more complexity and nutritional monitoring. Sleeve sits in the middle: simpler than bypass, stronger than medication, permanent anatomy. The honest comparison includes durability: surgery's 5-10 year data is extensive, while the medications require indefinite use with regain on stopping. Cost flips the math for many Americans: a lifetime of branded GLP-1s can exceed the one-time surgery price. Age and comorbidity profile decide candidacy more than preference does; severe reflux pushes toward bypass, high surgical risk pushes toward medication. Discuss all three with a bariatric program rather than choosing from internet anecdotes.
For informational purposes only, not medical advice. Consult a healthcare professional.
Frequently Asked Questions
How much weight will I lose with gastric sleeve?
On average 60-70% of excess weight within 12-18 months. For 60 kg of excess weight, that is 36-42 kg. Individual results vary with starting weight, habits, and follow-up.
How fast do you lose weight after gastric sleeve?
Fastest in months 1-3, steady through month 9, tapering to the lowest weight around 12-18 months. 10-20% regain by years 3-5 is common without sustained habits.
What is excess weight?
Current weight minus ideal body weight (Devine formula). Bariatric results are reported as percent of excess weight lost (%EWL) to compare across different starting weights.
Gastric sleeve vs bypass: which loses more?
Bypass averages slightly more (65-75% EWL vs 60-70%) with better diabetes remission and reflux outcomes, but higher complexity. Sleeve is simpler with fewer nutritional issues. The choice is individualized.
Will I regain weight after gastric sleeve?
Some regain (10-20% of lost weight) is common by years 3-5. Maintainers share habits: high protein, regular exercise, follow-up visits, no grazing, no liquid calories.
What can you eat after gastric sleeve?
Progression: liquids to purees to soft foods to regular small meals over ~6-8 weeks, then protein-first small meals lifelong. 60-80+ g protein/day, vitamins forever, no drinking with meals.
Does gastric sleeve cure diabetes?
It remits type 2 diabetes in roughly 60% of patients (higher with bypass), often within days from gut hormone changes before major weight loss. Remission needs ongoing monitoring; relapse occurs.
What are the risks of gastric sleeve?
Leak (1-2%), bleeding, stricture, worsened reflux, nutritional deficiencies, and rare mortality (<0.5% in accredited centers). Lifelong vitamin supplementation and follow-up are required.
Who qualifies for gastric sleeve?
Typically BMI β₯40, or β₯35 with obesity-related conditions (diabetes, hypertension, sleep apnea), after evaluated by a bariatric program including medical, nutritional, and psychological assessment.
Does insurance cover gastric sleeve?
Many US plans cover bariatric surgery with documented criteria (BMI thresholds, comorbidities, supervised weight-loss attempt, evaluations). Coverage varies widely; the program's coordinator navigates authorization.