As long as you stick to the diet and exercise recommendations, all types of weight loss surgery can achieve good, and often impressive, results.

However, rapid weight loss can cause complications. Read more about the risks of weight loss surgery.

Gastric band

A person with a gastric band should expect to lose 50% of their excess body weight within two years.

The weight loss is a gradual process, with:

• 35% of excess weight lost within six months of surgery
• 40% of excess weight lost by 12 months
• 50% of excess weight lost by 24 months

Expect to see a marked improvement in health conditions related to obesity, particularly:

• type 2 diabetes 
• gastro-oesophageal reflux disease (GORD) 
• obstructive sleep apnoea 
• high cholesterol 

Most people also report an improvement in their overall quality of life, in terms of:

• day-to-day pain and discomfort
• general physical health
• mental health

Gastric bypass

A person with a gastric bypass should expect to lose 70% of their excess body weight within two years.

The weight loss tends to be more rapid in the first year (60% of the excess weight lost) then slows in the second year, with only an additional 10% weight loss.

Again, expect to see a marked improvement in the health conditions above.