Vanaken began his career at the youth team of Lommel United before leaving the club to join the PSV Eindhoven academy in 2002 when the former declared bankruptcy.

[3] Vanaken was instrumental in Lokeren's run to the final of the 2013–14 Belgian Cup, playing in six of their seven matches and scoring one goal as his side edged out Zulte Waregem for the title.

[4] Vanaken further excelled in his second season in the top flight, scoring eight league goals and finishing third in the voting for the Belgian Golden Shoe award.

[5] It was announced in May 2015 that Lokeren had reached an agreement with Club Brugge over the transfer of Vanaken to the latter with the player signing a five-year deal subject to a medical.

[14] Vanaken made his debut for the Belgium national team on 7 September 2018, replacing Eden Hazard in a 4–0 victory against Scotland at Hampden Park.