What Is The Best Weight Loss Surgery? Here are some common questions about bariatric surgery like “what is the best weight loss surgery”. Consult your doctor to learn about their approach to the procedure and to discuss specific recommendations for your health. Bariatric surgery is the best and most effective treatment for morbid obesity (BMI 40 or more). About 65% of people who have bariatric surgery lose excess weight and keep it off for more than five years. More than 30 conditions are associated with obesity, such as hypertension, diabetes, heart disease, stroke, obstructive sleep apnea, and degenerative joint disease.