Joshua defends his WBA, IBF and WBO titles against unbeaten Usyk on Saturday.
While the heavyweight limit is uncapped, there has been speculation that Joshua has appeared leaner than usual in the build-up to this fight.
But he will be heavier by more than a stone against Usyk, the former undisputed world cruiserweight champion who came in at a career high 221.25lbs.
Joshua told Sky Sports: "I feel good. It could fluctuate, go lower, due to the styles of opponents, but I feel good at this weight.
"Maybe if I’m fighting a shorter, stronger guy I might bulk up a bit, but I’ve got a good fighter with his legs, so I’m going to keep up with his footwork and hand speed and make sure I’m good right through for the duration."
Joshua described Usyk as "a good heavyweight weight" after pair shared a tense stare-down.
"Larry Holmes, those types of guys were weighing about 100kg, Lennox (Lewis) and Vitali (Klitschko) were more 107kg, Mike Tyson was about the same, so it’s not a bad weight," Joshua said.
Joshua said he had full respect for his opponent and dismissed any suggestion the Ukrainian was afraid.
"No, no, no," Joshua said. "How many amateur fights has he had? About 400? He’s got no fear, he’s done it loads of times.
"This is business. There’s respect there and I like that sometimes. Sometimes you’ve got to give a bit of needle. Sometimes you just don’t like people and you don’t even know them, that’s how it is with certain fighters.
"But with him, I don’t know how he feels about me. He might think I’m a complete idiot, but I’ve got respect for him."