Several elements are fundamental :
- You sincerely want to loose much weight.
- Your Body Mass Index (BMI) is higher than 40, or 35 with complications of obesity.
- Your obesity is stable.
- You already made modes, which failed.
- You are between 18 and 60 years old.
- You are ready to modify your food practices.
- You are ready to take again a more constant and regular physical activity.