Yes, while many don’t have any food for breakfast the way Dr. Simeons laid out his original protocol, some do utilize some of their allotted calories and food items for breakfast and that is fine to do.
So some eat the P2 fruit for breakfast instead of with their lunch. You could also try having half your protein for breakfast – a 50 gram portion is definitely small but sometimes just having a little protein like that can help if you are struggling and I did that on occasion when I was on my final round of hCG.
That said, do be sure and check my input regarding attempting to continue exercise during hCG.
If you did do this, you may need to go beyond the 500 calorie diet and include a 3rd protein serving of 100g post workout.
I hope this helps!