Eating healthy without calorie counting

The last few weeks I’ve eliminated soda and beer, I don’t snack, and I eat what I consider to be fairly healthy meals. Today, for example, I had a banana for breakfast; some sushi that was just rice, fish and veggies; a celery juice, and a protein drink, for lunch. Then for dinner I had half a tuna fish sandwich. Most of my days are pretty similar, pretty fish and vegetable heavy. Also, usually around 4 bottles of water a day.

I have a fairly active job (massage therapist) and I work out fairly regularly (I manage about 3 days a week of I’d say high intensity [to exhaustion]).

Can I just do this? Do I really also need to start getting out the food scales, and measuring cups?