There is no specific answers for this. People might have specific allergies to something like peanut butter , but anything like medicine that is not recommended for you might cause you allergies and bad stuff
The answer is carbohydrates i believe
In boys, the first puberty change is enlargement of the scrorum and testes. At this point, the penis does not enlarge.
As the testes and scrotum continue to grow, the penis grows.
The first growth of pubic hair produces long, soft hair that is only in a small area around the genitals.
This hair becomes darker and courser as it continues to spread.
The pubic hair eventually looks like adult hair, but in a smaller area. It may spread towards the thighs and up to the stomach.
Body size will increase, Voice changes, and they start producing sperm.
The black specks are most likely just black oatmeal which has been grounded with the other piece.
Take bath instead of showers hope I helped