While Blachowicz will have to cut a good amount of weight to reach the 205-pound (93kg) weight limit, Adesanya – who is a fairly lean middleweight where he competes at 185 pounds (84kg) – says he isn't aiming to add any significant weight to match his opponent, even claiming that he could make 185 at the Saturday weigh-ins if he had to.
"Same flex, baby," Adesanya told ESPN. "Same thing. It's just silly to me when people go and decide to add more muscles to their frame that they're not used to over the years working this game."
He said he'll continue to work with his usual nutritionist Jordi Sullivan like he would a middleweight bout, saying it would be good "for my routine, my mind".
Blachowicz will likely put on more weight on fight night, as most fighters do following weigh-ins, which could see Adesanya give up a significant weight disadvantage, but the 31-year-old Kiwi says he's not worried and wants to "bring it back to the rawness of martial arts: technique".
"If I fought a guy that was 300 pounds, I could probably still beat him," Adesanya said, adding that he doesn't believe Blachowicz will be heavy enough to affect the result. "But there's a problem if he grabs me and decides to pin on me."
Adesanya has defended his middleweight title twice since becoming champion in October 2019 and is ranked the No. 4 pound-for-pound fighter in the world according to ESPN.
On Sunday, he will attempt to become just the fifth fighter in UFC history to hold titles from two different weight classes at the same time.
Joining Adesanya on the fight card will be two of his Kiwi City Kickboxing teammates Kai Kara-France and Carlos Ulberg.
Top 10 flyweight Kara-France will take on Brazillian Rogério Bontorin, while light heavyweight Ulberg will make his UFC debut against Kennedy Nzechukwu in a stacked card featuring three title fights.
Full fight card
Main card (4pm - Sky Sport PPV)
Jan Blachowicz (c) v Israel Adesanya (light heavyweight title fight)
Amanda Nunes (c) v Megan Anderson (featherweight title fight)
Petr Yan (c) v Aljamain Sterling (bantamweight title fight)
Islam Makhachev v Drew Dober (lightweight)
Thiago Santos v Aleksandar Rakic (light heavyweight)
Prelims (2pm - ESPN on Sky Sport)
Dominick Cruz v Casey Kenney (bantamweight)
Song Yadong v Kyler Phillips (bantamweight)
Joseph Benavidez v Askar Askarov (flyweight)
Kai Kara France v Rogerio Bontorin (flyweight)
Early prelims (12pm - UFC Fight Pass)
Tim Elliott v Jordan Espinosa (flyweight)
Carlos Ulberg v Kennedy Nzechukwu (light heavyweight)
Sean Brady v Jake Matthews (welterweight)
Livinha Souza v Amanda Lemos (strawweight)
Uros Medic v Aalon Cruz (lightweight)
Trevin Jones v Mario Bautista (bantamweight)
Kiwi fighter bios
Israel Adesanya (20-0)
· Age: 31
· Height: 193 cm (6 ft 4 in)
· Reach: 203 cm (80 in)
· UFC middleweight champion
· 15 wins via knockout
· Nickname: "The Last Stylebender"
Kai Kara-France (21-9)
· Age: 27
· Height: 163 cm (5 ft 4 in)
· Reach: 169cm (66.5 in)
· Ranked No. 8 in the flyweight division
· Nine wins via knockout, three via submission and one no contest
· Nickname: "Don't Blink"
Carlos Ulberg (3-0)
· Age: 30
· Height: 193cm (6 ft 4 in)
· Reach: 196cm (77.0 in)
· Making his UFC debut
· Two wins via knockout
· Nickname: "Black Jag"
Odds (TAB)
Israel Adesanya: $1.42
Jan Blachowicz: $2.70
How to watch
The main card of UFC 259 is available on Sky Arena pay per view for $39.99 and is available via streaming on Sky Sport Now pay per view at the same price. The prelims is available via ESPN on Sky Sport or Sky Sport Now. The early prelims are available exclusively on UFC Fight Pass.
