Final answer:
A varied and balanced diet, regular exercise, and meditation and mindfulness practices are the best nutritional preparations for stress.
Step-by-step explanation:
The best nutritional preparation for stress includes a combination of factors. A varied and balanced diet is key, as it provides the necessary nutrients to support the body's stress response. Regular exercise helps to reduce stress by increasing endorphin levels and improving overall well-being. Additionally, meditation and mindfulness practices can help calm the mind and alleviate stress.