As is typical for the genus Tangara, Green-and gold Tanager is omnivorous, with a diet that includes fruits and arthropods. In Yasuní National Park (Ecuador), it has been observed feeding fruits of Cecropia sciadophylla, Miconia and Blakea trees (Melastomataceae) (personal observations). In Peru, Green-and gold Tanager has been reported to eat Miconia, Ficus and Coussapoa (Gorchov et al. 1995). At one site in Bolivia, the fruit component of the diet was dominated by Miconia and Cestrum (Naoki 2003). The contents of stomachs from 18 specimens had contained vegetable material (14), animal material (2), or a mix of both (2) (Isler and Isler 1987, Willard et al. 1991).
Green-and-gold Tanager forages primarily in the midstory and canopy, typically higher than 8 m above the ground (Isler and Isler 1999, Munn 1995), but occasionally descends lower, especially in disturbed habitats (Naoki 2003).
Fruit primarily is taken with gleans (73% of all observations), followed by probes (14%) and other maneuvers. Arthropods also are taken with gleans (28% of all observations), followed by reach-down (17%), hang-down (15%), and reach-up (13%) maneuvers (Naoki 2003; prey capture definitions sensu Remsen and Robinson 1990). Very occasionally, also sallies or hover-gleans to capture arthropods (Isler and Isler 1999, Naoki 2003). Arthropods primarily are taken from leaves (61% of all observations), followed by slender bare branches (20%) and flower buds (17%).