The world’s most overweight man, Paul Mason left hospital last night after receiving lifesaving gastric bypass surgery. The 700 pound former-postal worker was reportedly in good spirits and even told people in the hospital that he wants to share his story with the world – through a weight loss guide.

The topic of his proposed book may sound surprising. However, Mason has more experience of losing weight than many would think. To become eligible for the procedure the Brit had to lose 280 pounds – more than 20 stone – a feat he managed to achieve in the space of just one year.

At his previous weight of 980 pounds he used to consume 20,000 calories each day, which is eight times more than an average daily consumption for men. In order to have the surgery performed he was required to travel to St Richard’s Hospital in East Sussex, in a specially reinforced ambulance.

Despite his impressive weight-loss Mason is still thought to be the world’s largest man. The title was previously held by Manuel Uribe but the 1,200 Mexican shed more than half of his weight this year. Mason will now have to monitor his diet extremely carefully and eat only small portions while his body adjusts to a new, smaller, stomach.

Mason is the world’s most prominent case of morbid obesity. Officially, a person is classed as morbidly obese when their body mass index (BMI) level goes above 40. The ideal weight is considered to be a BMI of between 18.5 and 25.

Recently, there has been an upsurge in the number of people going for operations to help them lose weight. For instance in the UK, a recent NHS report has revealed that the number of people using such operations has trebled. Ultimately most experts feel such surgery should be a last resort in the battle against obesity, and should only be used in extreme cases where there is an immediate health risk to the person in question.

Consult your doctor who may be able to prescribe you with a number of treatments, provided you are eligible. These treatments include Xenical.