Word for "food eaten only partially out of hunger"

Solution 1:

The first word that comes to mind is treat. From M-W dictionary (fairly far down on the page if you follow the link):

treat (noun): something that tastes good and that is not eaten often

As an example:

Your fresh chocolate chip cookies are a wonderful treat.

Solution 2:

Such a food item is called a delicacy:

OED II.12.b.: Something that gratifies the palate, a choice or dainty item of food; a dainty.

Collins 3. (Cookery) something that is considered choice to eat, such as caviar.

Cate is a synonym, not actually marked as obsolete in OED but not really attested there since the 1870s.

Solution 3:

Consider,

goody

goody (go͝od′ē) Informal

n. also goodie pl. goodies

Something attractive or delectable, especially something sweet to eat. FOD

Word associations show that many people react to the word "brown" with the instant response of "chocolate." It's a given that decadent goodies are usually a delicious chocolate brown (emphasis is mine.) Colors for Your Every Mood

decadent treat

decadent: characterized by or appealing to self-indulgence M-W

She slowly scooped a trail of chocolate from the plate with her finger, easing the decadent treat past her lips.

Solution 4:

Eating for flavor, and more generally doing anything just for pleasure, is sometimes called indulgence, and this word has slightly negative connotations. (For instance, note self-indulgence). One sense of to indulge is essentially to do whatever you please, beyond some proper restraint.

But the question isn't about the action, but about a word for food.

However, indulgence can refer not only in the act, but also to the object of the act. That is to say, a morsel of something tasty is an indulgence.

This sense is corroborated by Merriam-Webster, which gives one of the meanings as "something that is done or enjoyed as a special pleasure".

Solution 5:

All foods that have no dietary purpose are junk foods.

junk food, noun –Google

food that has low nutritional value, typically produced in the form of packaged snacks needing little or no preparation.

_{It's not a single word but it is 'a' noun and IMO, colloquially as close as you're going to get.}

Look at all the junk food! What, not hungry? There's always room for Jello.