Thailand is home to hundreds of thousands of monkeys, but most will not be known by name, wear tank tops or gorge on plentiful diets of junk food.

Enter Uncle Fatty and Godzilla, the legendary chunky monkeys whose lives of indulgence have earnt them fame, but have also had devastating consequences for their health.

Cruelly kept on a lead and raised on a diet of junk food, Godzilla's weight ballooned to more than 20kg, and he became a major tourist attraction at his owner's market stall in Bangkok.

He soon drew comparisons with Uncle Fatty, another popular overweight primate, who had tipped the scales at 27kg and was believed to be between 10 and 15 years old.