Āhāra: 'nutriment', 'Food', is used in the concrete sense as material Food and as such it belongs to derived materiality see: Khandha Summary I. In the figurative sense, as 'foundation' or sustaining condition, it is one of the 24 conditions Paccaya and is used to denote 4 kinds of nutriment, which are material and Mental:
1: material Food kabalinkārāhāra,
2: sensorial and Mental contact Phassa,
3: Mental intention mano-sañcetanā,
4: Consciousness Viññāna.
1: Material Food feeds the 8-fold materiality having nutrient essence as its 8th factor i.e. the solid, liquid, heat, motion, color, odour, the tastable and nutrient essence; see: Rūpa-kalāpa.
2: Sensorial and Mental contact is a condition for the 3 kinds of Feeling pleasant, painful and indifferent; see: Paticcasamuppāda 6.
3: Mental intention = Kamma feeds Rebirth;
see: paticca-samuppāda 2.
4: Consciousness feeds Mind and materiality, Nāma-Rūpa at the moment of conception Vis.M XI.