The smaller Blue Samurai open their World Cup account against Cameroon on June 14 in Bloemfontein, South Africa.
"I'd better let my players eat a lot and grow taller as countermeasures," Okada quipped, saying the Indomitable Lions could take advantage of their size.
"Cameroon usually play passing football but they may possibly hit our weak point by kicking long balls," he told Japanese media after returning from Europe where he met Japanese players and foreign coaches.
Okada said he got the hint when he had dinner with Wenger in London last week and sought his advice about fellow Frenchman and Cameroon coach Paul Le Guen.
"I asked him if Le Guen is an idealist or realist. Is he a person who follows his ideal or takes a realistic approach by adjusting to opponents?" Okada said. Wenger called Le Guen a realist. Le Guen was reported to have closely consulted Wenger before becoming manager of the Scottish side Rangers in 2006.
Cameroon, the four-time African champions, are known for passing football as well as long-ball attacks in the final minutes led by lanky striker Mohammadou Idrissou of Freiburg.
Okada, who has insisted on aiming for a semi-final spot despite being called unrealistic, plans to announce his 23-strong FIFA World Cup squad on 10 May.