Doctors are hoping to save the life of Santiago Mendoza, who weighs the same as an average 6-year-old. Santiago and his therapist Salvador Palacios are seen in this undated photo. Photo: CFP

Eight-month-old baby Santiago Mendoza has been put on an emergency diet - because he already weighs 20 kilograms.

Santiago, thought to be Colombia's heaviest baby, weighs about as much as the average 6-year-old.

His mother Eunice Fandino said her own "ignorance" was to blame for his weight gain.

"He was born with an anxiety," she said. "So if he cried I just fed him."

Santiago was flown to Bogota last weekend by volunteers from Gorditos de Corazon (the Chubby Hearts foundation) after his mother wrote to them asking for help.

He is now being assessed by medical specialists, the Daily Mail reported.

Salvador Palacio Gonzalez, director of the Chubby Hearts foundation, said doctors would try to cut his weight before several operations.

"Likely what he will need is long-term treatment, education, healthy foods and when he is older, physical activity," surgeon Cesar Ernesto Guevar told El Espectador.

"Otherwise, in the future he could suffer from diabetes, high blood pressure and severe problems with his joints."

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