Eman Abdul Atti, once known as the world's heaviest woman passed away on Monday due to complications from heart disease and kidney dysfunction.
Her family took her to Abu Dhabi's largest private hospital as they feared she would fall back into her old ways without medical support.
At one point, Atti reportedly weighed around 1,100lbs.
Earlier, Dr Yassin El Shahat, chief medical officer of Abu Dhabi's Burjeel Hospital had stated that after stage 2 of her treatment ends, Eman will be able to eat by mouth and use an electric chair after losing weight by following a strict diet.
She had since lost 140 kg before she was discharged from the city hospital for further treatment in the UAE in May. On March 7, she underwent bariatric surgery at the city's Saifee Hospital.
Ahmed was in Mumbai earlier this year and underwent a weight-loss surgery.
"Our prayers and heartfelt condolences go out to her family", said the hospital.
Eman had been treated by Dr Lakdawala and a team of around 15 doctors from various disciplines since she was brought here from Alexandria on February 11 this year.
However, Ahmed's sister Shaimaa, on social media, alleged that Ahmed was not receiving proper treatment at the privately-owned hospital in Mumbai.
She is now in post-operative care, it said.