World's fattest man Keith Martin dies at age 44

© Jenny Goodall/Daily Mail/REX

The world's fattest man Keith Martin

A Londoner who was officially the fattest man in the world has died.

Keith Martin, 44, died from pneumonia following a lengthy battle with his weight.

It happened just eight months after Mr Martin - who weighed 70 stone [980 pounds] at his heaviest - had undergone a successful gastric sleeve which removed three-quarters of his stomach.

Now the surgeon who tried to save him with life-changing weight-loss surgery is calling for the government to swiftly impose a fast-food tax as he backed NHS plans to offer more gastric surgeries to high-risk patients.

If he had lived he would have lost hundreds of pounds and regained his ability to walk and live a normal life, according to head surgeon Kesava Mannur who operated on Mr Martin at Homerton Hospital last year.

Mr Mannur supports new NHS guidelines which encourage doctors to suggest weight-loss surgery for anyone with a BMI higher than 30 and type 2 diabetes.

That means up to two million people could be eligible - and if they all agreed to surgery it would cost the NHS £12billion.

In the wake of Chancellor George Osborne's tax reform revelations in this week's autumn statement, Mr Mannur said: "The government needs to make unhealthy fast food more expensive.

"Otherwise we'll continue to see more and more people like Keith. In the past few years I have treated several people who weighed between 45 to 60 stone.

"In Keith's case, it's a shame because he'd had successful surgery despite being high-risk because of his size. It was unlucky he then caught pneumonia.

"Bariatric surgery can be a very good thing for the people who need it.

"We can't ignore they are here and they need help. Once a patient hits a BMI of 30-35 it is extremely difficult for them to lose weight on their own. If they are not treated they can require a lot of medical help which can be very costly.

"If they can get the weight off they can improve their health and mobility and maybe contribute to society rather than being a burden.

"But the thing that does need to change quickly is how easy it is for people to access very cheap, unhealthy fast food.

"Society needs to do more to encourage children to be healthy from a young age. They need to learn early about physical activity and a healthy diet.

"People need access to gyms and outdoor spaces where they can walk and play while feeling safe. It will be much better for everyone in the long run."

Before he died in March, unemployed Mr Martin admitted much of the weight had come from eating huge amounts of super-cheap fast food.

He would gorge on 20,000 calories a day - almost 10 times the recommended amount - having six-egg fry-ups for breakfast then pizzas, kebabs, Chinese takeaways and Big Macs for lunch and dinner all washed down with six pints of coffee and two litres of fizzy drinks.

He'd also snack on sandwiches, chocolate, crisps, sweets and biscuits.

Mr Mannur added: "Keith, like many people, had some emotional issues and he turned to food for comfort.

"That type of behaviour is nothing new, but what is new is how easy it is for people in that situation to buy a lot of cheap junk food."

Mr Martin left behind his two sisters - Sharon and Tina - who cared for him for many years leading up to his death.

Speaking from the home they shared in west London, Tina Martin said: "We're still grieving. We miss him very much."

Mr Martin's surgery was filmed for Channel 5 documentary 70 Stone & Almost Dead.

A hopeful Mr Martin said beforehand: "I'd resigned myself that either I was going to die in my bed or I was going to kill myself. But now I think 'you stupid person'.

"I'm a lot more confident than I used to be. I feel a lot happier.

"In a few months' time I want to be up and walking

"I know the only person to blame is me. All those years wasted. I'm not going to waste anymore of it. "

Having been stuck in his house for ten years and bedridden for several years due to his size, Mr Martin was able to drop 25 stone in order to qualify for the surgery after switching to a 2,000 calorie a day diet.

But just a week after the procedure he discharged himself from the hospital, against doctors' orders, because he was homesick.

By October 2013 he was back in hospital with septic shock and dehydration. Two weeks later he contracted pneumonia.

Mr Martin spent four months in hospital before he was released in February 2014, having been deemed medically fit. His weight had dropped to 39 stone [546 ponds].

After being transported home he said: "I feel great about surviving the operation.

"It gives me a chance now to go do some of the things I wanted to do - to get myself up and walking, take my dog Benji out for a walk.

"This is the end of one chapter and the beginning of a new chapter. Where it takes me I don't know, but it's going to be fun finding out."

But just a month later he was dead.

Prior to the weight-loss surgery, Mr Martin recorded a video message to his family in case he didn't survive.

He said: "Hi guys, I just wanted to let you know that I love you guys and thanks for being there for me. You can tell the rest of the family I love them and thanks for the support. Take care of each other."

Mr Martin's weight ballooned after he became seriously depressed in his twenties.

He blamed the binging on depression and anxiety which he developed after his mother died - also of pneumonia - when he was 16.

Mr Martin, who used to spend his days playing video games and watching TV, explained in 2012: "I started eating to ease the pain and before I knew it, I was binging every time something upset me.

"I've always been depressed. I am an agoraphobic - I'm afraid of public places - but it was never treated.

"I just want to be happy, without needing food to make me happy."