This section is from the book "Practical Dietetics With Special Reference To Diet In Disease", by William Gilman Thompson. Also available from Amazon: Practical Dietetics with Special Reference to Diet in Disease.
Insomnia is due to many causes, but those which concern dietetics are the opposite extremes of overfeeding and starvation or inanition. Overfeeding or eating improper food may cause disordered sleep, nightmares, or temporary insomnia from attacks of acute indigestion, dyspepsia, or biliousness, but inanition or malnutrition is more apt to cause true insomnia from exhaustion. Neurasthenic subjects whose nerve energy is insufficient to conduct their digestive. and absorptive functions completely are very liable to suffer from insomnia. They unfortunately resort to hypnotic drugs instead of first trying the efficacy of dietetics.
It is a good rule in such cases to improve the nutrition by carefully regulated feeding at frequent intervals. In addition to three good meals a day, the patient should be made to take one or two quarts of milk, with beef tea and one or two ounces of malt extract. By gradually increasing the diet according to such rules as those given for the treatment of neurasthenia, in a week or ten days the patient can often be made to reach the maximum above given, and improvement is almost certain to follow. It is best to take the heaviest meal of the day in the early afternoon not as late as six o'clock, for an overloaded stomach with indigestion is itself a cause of insomnia, but, on the other hand, going to bed with a perfectly empty stomach is usually undesirable. In mild cases a glass of hot milk, a couple of teaspoonfuls of meat extract in hot water, or a cup of good beef tea and a biscuit, or a cup of cocoa, or chicken broth, or a light sandwich and a glass or two of beer or ale, taken just before retiring, will serve to divert the blood current from the brain to the stomach and induce cerebral anaemia and sleep without the use of medicines, stimulants, or "nightcaps," and if anodynes have to be given, a little food taken in this manner increases their efficacy and makes a smaller dose possible.