Learn Portuguese (Portugal): É bom comer fruta todos os dias.

We use É to state a general, timeless fact: eating fruit is inherently a good thing. If you were eating an apple right now and wanted to say it tastes good, you would use a temporary state and say Está bom!.

Why is the verb comer in the infinitive (dictionary) form instead of being conjugated?

When you start a sentence with a general, impersonal phrase like É bom (It is good), É fácil (It is easy), or É importante (It is important), the action that follows stays in the infinitive form.

Why doesn't fruta have an article like a (the) in front of it?

Just like in English, Portuguese can drop the article when talking about an uncountable noun in a broad, general sense. You are talking about the category of food, not a specific piece of fruit.

What is the difference between fruta and fruto?

Fruta is the everyday culinary word for the sweet fruit you eat as food. Fruto is mostly a scientific or botanical term for the seed-bearing part of a plant, or it is used metaphorically like the 'fruits' of your hard work.