The world's oldest man just turned 113. His secret? Eating candy.

The year Masazo Nonaka was born, Albert Einstein published his paper on the theory of relativity, Theodore Roosevelt was inaugurated as the 26th president of the United States, and Bertha von Suttner became the first woman to win the Nobel Peace Prize. It was 1905.

Now, 113 years later, Nonaka is now the oldest man alive, according to Guinness World Records. And on Wednesday, he'll celebrate his 113th birthday.

Nonaka was awarded the title in April after Francisco Nuñez Olivera of Spain passed away at age 113 in January.

According to Guinness, Nonaka grew up with six brothers and one sister in Ashoro, a small town in Hokkaido, the northernmost of Japan's four main islands. In 1931, he married a woman named Hatsuno, with whom he had five children. According to the Independent, Nonaka ran an inn in Ashoro for most of his life near the town's renowned hot springs.

Nonaka attributes his longevity to soaking in the mineral-rich springs, as well as his love of sweets. His daughter told Guinness she thinks it's because he leads a stress-free life: "If he doesn't want something, he'll make sure everyone knows about it."

He has spent most of his long retirement reading the newspaper after breakfast, watching samurai shows and sumo wrestling on television and looking after his pets, two cats named Haru and Kuro, who receive the table scraps when Nonaka doesn't care for his dinner.

Nonaka joins a considerable list of Japanese people who have held the titles of oldest living man or woman. In 2017, the country had a record 67,824 people over the age of 100 - approximately 88 percent of whom are women. Nabi Tajima, a Japanese woman, was the oldest living person until her death in April at the age 117. The oldest man ever was also Japanese: Jiroemon Kimura, who died in 2013 at the age of 116.

Such widespread longevity does come at a cost. Japan's population has the highest proportion of people over 65 in the world, but birthrates are falling and the country is struggling to shoulder the responsibility of caring for the country's many retirees.

But Nonaka's title hasn't come without controversy. Fredie Blom, a South African who celebrated his 114th birthday in May, is widely believed to be the oldest living man. Guinness World Records told The Post at the time that Blom was not being considered for any award.

"We ask for a great deal of paperwork and proof to substantiate claims that meet our official guidelines," a spokeswoman told The Post at the time. "We also work with various expert gerontologists and consultants who assist in the investigation of such claims to ensure our facts are correct."

But she said that if Blom wants to apply, Guinness will work to determine his eligibility.

Nonaka, for his part, probably won't be paying much attention to his competitor as he rings in 113. If past celebrations are any indication, he'll be celebrating with sweets.