Bullying and failure in life
Notify the supervisor of said coworker, and I would speak to that person to get a deeper understanding and hopefully tell them that it is not proper for us to act in such a manner.
Malnutrition occurs when the body doesn't get enough nutrients.
(Causes include a poor diet, digestive conditions, or another disease.
Symptoms are fatigue, dizziness, and weight loss. Untreated malnutrition can cause physical or mental disability.)