By Haziq Qadri @haziq_qadri
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Videographer / Director: Lalit Jain
Producer: Haziq Qadri, Basit Umer, Nick Johnson
Editor: Joshua Douglas
In March 2015, 18-month-old Aliya Saleem weighed 2st 13lbs (41lbs) and her incredible size garnered worldwide attention.
A video about Aliya and her family’s ordeal received more than 21 million views on YouTube channel Barcroft TV.
But her mother Shabnam Parveen and father Mohammad Saleem were left baffled by what was causing their daughter's insatiable appetite.
Now a paediatrician at the Orchid Medical Centre in the Indian district of Ranchi has formulated a number of theories about what could be behind Aliya's ever-expanding waistline.
Dr Bhavya Kumar has examined Aliya and believes she could be suffering from Prader-Willi syndrome - a rare disorder characterised by learning difficulties, growth abnormalities, and obsessive eating.
He said: "There could be some hormonal imbalance, there could some metabolic disease. There can be some genetic causes.
"It could be because of some tumour. But because there is a history of sibling loss with similar complaints, that points towards a genetic cause.
"So, I strongly suspect that this could be a case of some genetic disorder, most probably Prader-Willi syndrome, which is a very rare disorder.”
However, in order to make a definitive diagnosis, Dr Kumar has a number of other tests he would like to run on Aliya.
He added: "We would like to get her hormones levels checked. We would like to get her organ function test done. So that we can see that all her organs are functioning properly.
"We would like to screen her for diabetes, a thyroid function test, her cortisol levels need to be done. We need to see her growth hormone levels as well.
"We will do an MRI scan to see her hypothalamus, an ultrasound to see her adrenals. And apart from that an x-ray to see her boneage. And definitely a karyotyping.
"That would rule out any genetic causes. And only after doing all those things, we would be probably able to make the diagnosis and then we can take it further from there."
The 18-month-old lives with her family in a remote Indian village in the state of Jharkhand.
She weighed roughly 9lbs at birth, but started ballooning in size three months later.
Shabnam and Mohammad find her condition especially painful after another one of their daughters died in similar circumstances.
Shabnam recounts how her daughter was eating her lunch when she suddenly collapsed with a brain haemorrhage.
She said: "Simran too suffered from weight issues and ate excessively, just like Aliya.
“The family had shifted to Gujarat for Simran’s treatment, but the doctors could not pinpoint the cause for the excessive weight gain.”
According to Shabnam, Aliya requires three times the amount of food of a normal child her age.
Her parents have told how they have to feed their daughter constantly - as otherwise she breaks down in tears and throws temper tantrums.
Mohammad works as a tailor and brings in roughly £2 a day - with a huge portion of his wages going towards the feeding costs of his daughter.
Shabnam and Mohammad have a five-year-old son called Ali who is a regular weight.
Shabnam said: “We spend all our money to feed Aliya.
"If we do not give her something to eat, she cries endlessly and gets cranky.
"Her constant hunger leads to excessive weight gain due to which we have to buy new sets of clothes every two weeks that take a toll on our limited expenses."