Which action is characteristic of mental illness

1.emotional pain after ending a friendship.

2.brushing teeth every hours because ones mouth feels dirty.

3.feeling embrassed about going to school after falling in front of ones friend.

starvation is bad because your body needs nutrition and to deprive it of nutrition can cause problems with both health and fitness.

explanation:

it can make weight loss slow down over time, but it won't cause someone to gain weight depsite restricting calories. starvation causes weakness in the senses like thirst.