But whatever hours may be selected as most convenient for meals, they should be uniform; and for this reason -- at the hour when the stomach is accustomed to receive food, the appetite is sharper generally, and the gastric juices more copious, than they are immediately before or after that time. If food be taken before the accustomed hour, the stomach is, as it were, taken by surprise, and is not found in perfect readiness to receive it; if the meal is delayed beyond the accustomed time, common experience teaches that the appetite is liable to lose its sharpness; there is, for a while, less inclination to take food. The objection, however, against delaying a meal beyond the usual time, is very small compared with the objections against eating too soon; because when a meal or luncheon is taken soon after a previous one, the stomach has not had sufficient time to go through with the digestive process, and to recruit its energies for another effort. But when a meal is delayed longer than usual, though the appetite may lose its sharpness for a short time, yet it will return again; and the digestive power of the stomach will not have been impaired, unless the period of abstinence should be of long continuance.

In the arrangement of regular meals, regard should be had to the hour of rest at night. Ten o'clock, as will hereafter be considered, is a favorable hour for retirement; and no food should be previously taken in all ordinary cases within the space of two or three hours. If food be taken too near the time of sleep, so as to leave no chance for the more active parts of the digestive process to be performed, there will be found generally a dull, heavy pain in the head on the following morning, with diminished appetite. The food has laid comparatively undigested through the night; because when we sleep, the whole system is in a quiescent state; the nerves which are called into action in the process of digestion, are, during healthy sleep, inactive. A late supper generally occasions deranged and disturbed sleep; there is an effort on the part of the nerves to he quiet, while the burdened stomach makes an effort to call them into action; and between these two contending efforts, there is disturbance -- a sort of gastric riot -- during the whole night. This disturbance has sometimes terminated in a fit of apoplexy and in death.

Source: http://chestofbooks.com/health/natural-cure/Health-Without-Medicine/Dietetic-Rules-Time-For-Eating.html