What was Adam's punishment for eating the forbidden fruit?

Answer: Painful toil for his food

The ground was cursed because of Adam, and he would toil painfully for food.

“And to Adam He said: “Because you have listened to the voice of your wife and have eaten from the tree of which I commanded you not to eat, cursed is the ground because of you; through toil you will eat of it all the days of your life.”— Genesis 3:17 (BSB)