In brief, AN 4.57 speaks of long life, beauty, happiness, and strength as karmic results of the act of offering food. Now bare in mind that this discourse has no parallel even in the Pali Canon. But the MN 135 has 17 parallels. Therefore, in this case, it’s safe to assume the teachings given in the MN 135 are authentic. According to MN 135, refraining from the destruction of life will result long life. And, refraining from anger will result beauty. The strength can be taken as an attribute of being healthy which is a result of being refrain from harming beings. The happiness is an universal outcome due to one or many wholesome results.
Interestingly, there’s a story in Vinaya where Suppavāsā (the devotee mentioned in AN 4.57) said to cut flesh from her thigh to cook for a monk who craved to eat meat!
As in the AN 4.57, the same later tendency of attributing various good outcomes of a single action also can be seen in Dhammapada 109 where it speaks of long life, beauty, happiness, and strength as outcomes of performing service and paying respect to elders/superiors. The service and respect may have become wanting at a later time in India as they were able to take two separate places in the above mentioned list of 10 meritorious actions. In some Asian Buddhist communities, this stanza also used as a blessing mantra at the end of meetings/functions if a monk is available there to chant it.
Interestingly, Dhammapada 109 also without any parallel except in the ancient Indian “Laws of Manu” (Manusmṛti).
Isn’t refraining from unwholesome itself a wholesome action?
As my availability with an online facility ends today, I won’t be able to participate further in the discussion for some time.