Bariatric Surgery
Excess weight loss is the measure surgeons use to judge success.
When you read about bariatric surgery results, you will see terms such as excess weight loss and total body weight loss. These measures help surgeon and patient judge results objectively, beyond the number on the scale. In this article we explain each one with a real example from a clinical study co-authored by Dr. Ahmed Shinkar.
💡 Key Takeaways
- Excess weight is the difference between your current weight and your ideal weight.
- Losing more than 50% of excess weight is considered a successful result.
- Total body weight loss compares what you lost with your weight before surgery.
- In the study, patients lost more than 78% of their excess weight within a year.
First: What Are Ideal Weight and Excess Weight?
Ideal weight is usually calculated using a BMI of 25, so it depends on height. In the study, for example, the patients’ median ideal weight was about 66 kg.
Excess weight is the difference between your weight before surgery and your ideal weight. If you weigh 156 kg and your ideal weight is 66 kg, your excess weight is 90 kg.
How Is Excess Weight Loss Calculated?
📐 The formula
- Excess weight loss % = (weight lost ÷ excess weight) × 100
Back to the example: if you reach 83 kg after a year, you have lost 73 kg of 90 excess kilograms. That is about 81% excess weight loss, an excellent result.
What Is Total Body Weight Loss?
📐 The formula
- Total body weight loss % = (weight lost ÷ weight before surgery) × 100
In the same example: 73 ÷ 156 × 100 = about 47%. Many researchers prefer this measure because it does not depend on how ideal weight is defined, and it reflects the real change in the body.
Excess Weight Loss in the Study
The study published in the Journal of Gastrointestinal Surgery measured both in 92 patients with super obesity:
| Time | Excess – sleeve | Excess – mini bypass | Total – sleeve | Total – mini bypass |
|---|---|---|---|---|
| 3 months | 32.8% | 29.1% | 18.5% | 16.8% |
| 6 months | 51.6% | 48.7% | 29.1% | 28.7% |
| 12 months | 78.2% | 86.6% | 43.3% | 50.4% |
Both groups passed the 50% mark that signals clinical success, and went far beyond it within a single year.
Success Is More Than a Number
Better Health
Improvement in diabetes, blood pressure and sleep apnea is a key sign of success. Read about diabetes and bariatric surgery.
Healthy Blood Tests
Losing weight while keeping iron, protein and vitamins in the normal range.
Quality of Life
Moving easily, feeling confident, and enjoying everyday activities.
FAQs About Excess Weight Loss
What percentage means bariatric surgery was successful?
Surgery is usually considered successful when a patient loses more than 50% of excess weight and keeps it off long term.
Which is more accurate: excess or total weight loss?
Each has its use. Excess weight loss links the result to an ideal target, while total weight loss is simpler and not affected by how ideal weight is defined.
Do I need to reach my exact ideal weight?
Not necessarily. The main goal is better health, improvement in related conditions, and a weight you can maintain.
How do I calculate my ideal weight?
Multiply your height in meters squared by 25. For a height of 1.63 m: 1.63 × 1.63 × 25 = about 66 kg.
Find Out Your Expected Excess Weight Loss
Book a consultation with Dr. Ahmed Shinkar to assess your case and set a realistic weight goal.
Book Your ConsultationDisclaimer: This article is for educational purposes only and does not replace a consultation with a qualified physician.