Leonid Stadnyk was formerly listed as the world’s tallest living man according to Guinness World Records.  On August 20, 2008, editor-in-chief of Guinness World Records, Craig Glenday, announced that the title of world’s tallest man had been returned to China’s Bao Xishun after Stadnyk refused to be measured under the Guinness standard guidelines requiring several measurements throughout the course of 24 hours under the watchful eye of a Guinness Book representative. Guinness then averages the height readings to come up with a final official measured height.

On August 8, 2007, Guinness book’s spokeswoman Amarilis Espinoza stated that in the 2008 edition of the record book, Mr. Stadnyk appeared to be taller than Bao Xishun, a native of Inner Mongolia in China who stands 7 ft 8.9 in (2.360 m). Although he held the title for a few months, Stadnyk refused to be measured and was consequently denied the GWR recognition. Others have questioned the legitimacy of his record, noting that Stadnyk has never been officially measured by Guinness World Records, only by the “Ukrainian Book of Records” that says that he measures 2.57 m (8 ft 5.2 in), and that the doctor originally credited by Guinness with confirming Stadnyk’s height had denied ever measuring him.

Stadnyk’s excessive growth began after brain surgery at the age of 14, after which he developed a pituitary gland tumor that caused the gland to secrete large amounts of growth hormone. This resulted in what doctors describe as acromegalic gigantism. Twenty years after the surgery, the doctors discovered the tumour had mysteriously disappeared and he was currently healthy. A Pravda news report in Spring 2006 reported that Stadnyk grew 2 cm (0.79 in) in the previous year, not accounting for the time between the original Spring 2004 report and Spring 2005. He reportedly wore European size 62 shoes (US size 28). According to Pravda[citation needed], his health was slowly failing in that he needed to hold on to limbs of trees and the side of his house to walk about. His official recorded weight was listed at 200 kg (440 lb).  Stadnyk died at the age of 44 on August 24, 2014 from a brain hemorrhage.