As they say one man's food is another man's poison. You know yourself better and thus you know what works better for you. If this pattern of eating only lunch is okay by you and it doesn't have any effect on your general well being, you can keep up.
As for me, opposite is the case because I always try to eat breakfast no matter where I am rushing to in the morning. And also ensure I must eat dinner before going to bed because if I don't, I can't sleep well at night. Although it is not all the time I am consistent with this pattern, because there are times the bowel will refuse to clean itself up, and for this reason I might not see the need to fill it up, because I usually don't eat unless I am hungry. Hence I only eat when I am hungry even though it's lunch which I often skip. Interestingly, there are times I can stay a whole day without eating maybe until I am hungry. In this case, I might decide to eat only once in a day too just like you.