When cooking 'Mighty' food or elixirs, they grant differing levels of Attack Boosts determined by the ingredients that are combined.
How much outgoing damage is added per level of the boost?
When cooking 'Mighty' food or elixirs, they grant differing levels of Attack Boosts determined by the ingredients that are combined.
How much outgoing damage is added per level of the boost?
So I just tested this using the method suggested by @Seiyria.
These following results are gathered while wearing the Champions Tunic, and using each tier of food against the same enemy at full health.
+--------------------+----------+----+----+----+
| Weapon | Standard | T1 | T2 | T3 |
+--------------------+----------+----+----+----+
| Torch | 2 | 2 | 2 | 3 |
| Woodcutters Axe | 3 | 3 | 3 | 4 |
| Throwing Spear | 6 | 7 | 7 | 9 |
| Iron Sledgehammer | 12 | 14 | 15 | 18 |
| Guardian Sword | 20 | 24 | 26 | 30 |
| Knights Broadsword | 26 | 31 | 33 | 39 |
| Guardian Sword+ | 30 | 36 | 39 | 45 |
| Guardian Sword++ | 40 | 48 | 52 | 60 |
| Ancient Battleaxe++| 60 | 72 | 78 | 90 |
+--------------------+----------+----+----+----+
As indicated by this data, the Percentual Increases are:
(after rounding)
Ancient armor proficiency bonus stacks with atk up food as they are different classes of buffs. Further, guardian weapons found from test of strength shrines have a native 30% dmg buff against guardians and the ancient weapons bought from the lab have 50% dmg against guardians.
So the ancient proficiency bonus of 80 on an ancient weapon for 50 plus the atk food bonus of 50 comes out to 180%. Guardians be wrecked. Ancient arrows should always be shot from an ancient bow for this reason.