Juanita Valentina Hernandez is just 10 months old but weighs the same as an average five-year-old.While the youngster was a normal 6lb when she was born, she began to expand rapidly in size just weeks later.
She now tips the scales at 44lb (20kgs or just over three stone) and is undergoing tests to determine the cause of her surprise weight gain.
The average 10-month-old baby should weigh 19lb or 8.5kg, Tam Fry, Patron of the Child Growth Foundation, told MailOnline.
He said: 'Weight can vary with ethnicity, but regardless of that, this child is vastly, vastly overweight. It is tragic
.'
Juanita's anxious mother, Sandra Franco, from Libano, Colombia, said she has no idea what has caused her daughter to balloon in size.
'When she was 15 days old she was already looking chubby, because she was born very thin,' she explained.
'Since then she's been gaining weight. Now she is 10 months old and I have realised she is morbidly obese.'
She added: 'Until now I haven't been able to treat her because I am unemployed and didn't have the money.'
Mr Fry explained there are various medical conditions which can cause rapid weight gain in children.
These include Prader-Willi syndrome, which causes a permanent feeling of hunger and can easily lead to dangerous weight gain.
Conditions such as Cushings sydrome - where high levels of the stress hormone cortisol can cause weight gain - and Beckwith-Wiedemann syndrome, known as an 'overgrowth syndrome' can also cause children to expand in size rapidly.Last month Colombian charity Gorditos de Corazon - Chubby Hearts - brought Juanita to the capital, Bogota, where a team of specialists began treatment.
