“What I don’t understand is, how sukha vedana can arise while eating tasty food or smelling a nice odor.”
That is a good observation. Here is another thing to think about: kama guna that are based on one’s bhava:
Kāma Guna, Kāma, Kāma Rāga, Kāmaccanda
Obviously, an Arahant also tastes the sweetness of sugar. Does that count as a “sukha vedana”? May be this needs to be decided at how a “sukha vedana” is defined.
Is “sukha vedana” defined as “a bodily sensation”? If so, sweetness of sugar would not count as a sukha vedana.
– However, since “somanassa” is defined as a “mental construction”, sweetness of sugar would not count as a somanassa vedana either!
– May be it is a “mental construction” that happens AUTOMATICALLY based on bhava.
– For example, humans like the taste of sugar, but a pig does not, which likes the taste of feces. So, just being a human one feels sugar as likable or tasty.