"I eat fruit as often as possible."
Translation:Ithim torthaí chomh minic agus is féidir.
If you replaced "fruit" with "vegetable" would you say "I eat vegetable as often as possible" or "I eat vegetables as often as possible"?
That tells you that the "fruit" in this sentence is actually a mass noun rather than the singular ("a fruit"), and therefore the plural torthaí is more appropriate than the singular toradh.
The analytic form in the 1st person singular present tense is only available for the veb bí, where both táim and tá mé are accepted. For all other verbs, the 1st person singular present tense is the synthetic form only.
This is the case for all dialects.