For breakfast I always have my manually squeezed OJ juice, toasted bread with EVOO and rubbed tomaoe with iberic jam (jummy), this gives me good quality fats, protein and vitamin C, for macros and to fill the required kcals before I go to the gym make a milkshake of 1 banana, cinnamon and milk.
The thing is sometimes I get discomfort that lasts through the day. I don't know if it's the combination of milk + juice, but i've heard it's perfectly ok to have them on the same meal.
Then there is the whole banana thing where the moons have to aling to get a perfectly fine tuned ripe banana to eat.
What about the cinnamon?
The rest don't give me any discomfort. Plus the fact sometimes it happens and some it doesn't makes it even more random. Im just asking you for your opinion.