Food items restore your HP, they don't grant you more HP.
Example: you have 100 maximum HP and are hurt, bringing you down to 79 HP. You drink an orange juice that ordinarily grants you 22 HP. Since you are only missing 21 HP then these 21 HP are restored and the 1 remaining HP granted by the juice has no effect (is wasted).
Food items restore your HP, they don't grant you more HP.
Example: you have 100 maximum HP and are hurt, bringing you down to 79 HP. You drink an orange juice that ordinarily grants you 22 HP. Since you are only missing 21 HP then these 21 HP are restored and the 1 remaining HP granted by the juice has no effect (is wasted).
Thank you - there was indeed some confusion. Maybe a change in wording might be helpful?