Author: Mr Stewart Skinner
Most medical interventions are able to achieve some initial weight loss, but an adequate degree of weight loss, and preventing weight regain, are the most difficult goals to achieve.
Medical studies of intensive diet and exercise programs have shown that the best weight loss that can be achieved for dieting is about 15% of excess weight. This compares to the various weight loss operations which are able to achieve weight loss of more than 50% of excess weight. Furthermore, the long term results for dieting show that after one year, about 50% of weight is regained and after 2 years, nearly 90% of weight is regained.
This compares to weight loss operations which have been shown to be more durable, maintaining weight loss well beyond 2 years. In 2018, we published our 20 year results for the Lapband operation, the longest follow-up data ever published for a weight loss operation (1). This showed a sustained weight loss of 49% of excess weight over 20 years. There are no comparable long term studies for sleeve gastrectomy or gastric bypass.
Long term studies of weight loss operations have found that 1 in 6 patients (about 16%) will regain more than 10% of the initial weight that they have lost. There are a number of factors that can lead to weight regain. Firstly, there can be factors related to the surgical operation. For Lapband surgery, there may be a leak from the Lapband prosthesis leading to loss of restriction. For sleeve gastrectomy or gastric bypass, the remnant stomach can expand in time allowing greater food intake. For gastric bypass, the outlet can expand allowing the stomach to empty faster. Each of these problems require further surgery to remedy them. Secondly, there may be dietary reasons. There may be a tendency to consumption of high calorie foods, or there may be poor eating behaviours such as grazing or binge eating. Weight loss operations work by causing a restriction to eating, but more importantly, by taking away the feeling of hunger. These 2 effects of weight loss operations therefore make it easier to stick to a diet. Weight loss after surgery still requires a life-long commitment to dieting. There is no operation that can stop people choosing to eat high calorie foods or continuing to eat when they are not hungry. Therefore, these poor eating habits can lead to weight regain. Regular follow-up with regular medical appointments has also been shown to be an important factor in achieving and maintaining weight loss. Insufficient physical activity can also lead to weight regain.
So the good news is that more than 80% of patients will maintain their weight loss in the long term, after weight loss surgery, as long as there is a commitment to regular follow-up and a life-long commitment to the eating restrictions and regular physical activity.
| Year | No. of patients | Weight loss (kg) | Change of BMI (units) | %EWL | % follow-up |
| 0 | 8378 | 0 | 0 | 0 | |
| 1 | 7817 | 21.9 | 7.8 | 45.8 | 92.5 |
| 2 | 7264 | 24.6 | 8.8 | 52.6 | 89.1 |
| 3 | 6877 | 24.5 | 8.7 | 51.4 | 85.0 |
| 4 | 6006 | 24.0 | 8.6 | 49.3 | 69.4 |
| 5 | 5235 | 23.7 | 8.5 | 47.7 | 68.6 |
| 6 | 4570 | 23.2 | 8.3 | 46.4 | 55.0 |
| 7 | 3917 | 22.9 | 8.2 | 45.6 | 46.6 |
| 8 | 3333 | 23.1 | 8.3 | 45.5 | 43.9 |
| 9 | 2768 | 22.9 | 8.2 | 44.8 | 41.9 |
| 10 | 2275 | 23.2 | 8.3 | 45.5 | 39.0 |
| 11 | 1860 | 23.6 | 8.5 | 45.6 | 43.8 |
| 12 | 1472 | 24.1 | 8.7 | 46.7 | 36.6 |
| 13 | 1147 | 24.4 | 8.8 | 46.8 | 41.3 |
| 14 | 827 | 25.4 | 9.1 | 47.7 | 33.8 |
| 15 | 599 | 25.4 | 9.1 | 47.9 | 34.0 |
| 16 | 436 | 25 | 9.0 | 47.1 | 36.5 |
| 17 | 292 | 26.4 | 9.5 | 48.3 | 27.9 |
| 18 | 181 | 27.2 | 9.6 | 47.3 | 23.8 |
| 19 | 95 | 27.2 | 9.5 | 46.1 | 24.6 |
| 20 | 35 | 30.1 | 10.6 | 48.9 | 25.0 |
(1) Long-Term Outcomes After Bariatric Surgery: a Systematic Review and Meta-analysis of Weight Loss at 10 or More Years for All Bariatric Procedures and a Single-Centre Review of 20-Year Outcomes After Adjustable Gastric Banding. Obesity Surgery, 2018. 23(9) 1-12.