• āhāra

'nutriment', 'food', 

is used in the concrete sense as material food and as such it belongs to derived corporeality (s. khandha, Summary I.) 

In the figurative sense, as 'foundation' or 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) impression (phassa), 
3. mental volition (mano-sañcetanā), 
4. consciousness (viññāna).

1. Material food feeds the eightfold corporeality having nutrient essence as its 8th factor (i.e. the solid, liquid, heat, motion, colour, odour, the tastable and nutrient essence; s. rūpa-kalāpa). 
2. Sensorial and mental impression is a condition for the 3 kinds of feeling (agreeable, disagreeable and indifferent); s. paticcasamuppāda (6). 
3. Mental volition (= karma) feeds rebirth; s. paticca-samuppāda (2). 
4. Consciousness feeds mind and corporeality (nāma-rūpa; ib., 2) at the moment of conception" (Vis.M. XI).

Literature (on the 4 Nutriments):

• M. 9 & Com. (tr. in 'R. Und.'),
• M 38;
• S. XII, 11, 63, 64 -
• The Four Nutriments of Life, Selected texts & Com. (WHEEL 105/106).