Meals usually take no article (have breakfast), but you can use a/the when the meal is specific.
Zero article for general meals; a/the for specific meals.
Don’t add 'the' automatically before meal words when you mean the general activity.
Did you have breakfast? / What did you have for breakfast?
💡 Zero article is the default for meals as routine activities. Use a/the when you treat the meal like a countable event or a specific meal.
✓We had breakfast at 8.
✗We had the breakfast at 8. (general)
General routine meal → no article.
✓The breakfast they served was delicious.
✗Breakfast they served was delicious.
Specific breakfast (defined by a clause) often takes 'the'.
✓Let’s have a quick lunch.
Treating lunch as one event; 'a' is common with adjectives.