 Over 50% of François' langur's diet is made up of leaves.It also consumes fruits (17.2%), seeds (14.2%), flowers, stems, roots, bark, and occasionally minerals and insects from rock surfaces and cliffs.This langur consumes its favorite food, young leaves, at the highest rate during the dry season, April through September; between October and March when young leaves are less common, the langur supplements its diet with seeds, petioles, and stems.