If you feel thin and weak, focus on a balanced, calorie-rich diet with good protein (eggs, milk, pulses, nuts), whole grains, fruits, and healthy fats, along with regular meals and proper sleep. Light strength exercises can help build muscle and improve energy. You may take supplements like Multivitamins if needed, but it?s better to improve diet first. If weakness persists, get checked for conditions like Anemia or thyroid issues with a doctor.