A mental man does not have no disease, as mental illness is a medical condition that can affect anyone and is treatable: 

Mental health
Mental health is a person’s overall well-being, which includes how they think, feel, and behave. It’s an important part of health and well-being, and it’s influenced by and can influence physical health. 

Mental illness
A mental illness is a medical condition that can affect a person’s mental health. Mental illnesses can range from mild to severe, and they can affect anyone regardless of age, gender, race, or other factors. 

Treatment
Mental health conditions are treatable, and there are many ways to manage them. Treatments depend on the type and severity of the illness. 

Organizations
There are several organizations that can help with mental health, including the National Alliance on Mental Illness,
mental person is fit for his body due to 1.Exercising regularly
2.Eating healthy non healthy meals
3.Getting enough sleep
4.Practicing gratitude
5.Focusing on positivity
6.Staying connected with all peoples