Referring this question Dr. `Abdul Fattah Idrees said:
If the distance a Person is traveling is over 85 kilometers, which is the estimated distance to enjoy the license of shortening Prayers, and he finds it difficult to keep fasting, then he may enjoy the dispensation given for travelers to break fasting and make up for the missed days later in suitable times. But if the distance is shorter than this, then he has to observe fasting.