We do not use articles with the names of meals.
We will have a lunch at 1pm.
We will have lunch at 1pm.
If you talk about a particular meal then we use the article.
- The breakfast we had yesterday was wonderful.
- The dinner in that Indonesian restaurant was special.
If you use an adjective before the name of the meal then we use articles.
- I had a big breakfast, so I’m not very hungry.
(adjective/big) - A three-course dinner will be served at 8pm.
(adjective/three-course)