Using FoodComponent API you can set Nutrition/Saturation however the changes do not affect the item in the desired way

food components were marked on path "food" until 1.21.2, now them are marked as "consumable"

an edited item with spigot api where you set nutrition as 10 becomes

stone[food=\{nutrition:10,saturation:0.0f}]

while it should be

stone[consumable=\{nutrition:10,saturation:0.0f}]

food components now require consumable component to be eatable

stone[food=\{nutrition:10,saturation:0.0f}]

cannot be eaten, require to be

stone[consumable={},food=\{nutrition:10,saturation:0.0f}]

consume seconds goes on consumable component

stone[consumable=\{consume_seconds:1.6f},food=\{nutrition:10,saturation:0.0f}]