Interference in the action of the kidneys is apt to result in a retention within the system of the elements, which the kidneys, in normal condition, eliminate from the system, such as urea, uric acid, urates, sulphuric acid, sulphates, sodium phosphate, xanthin bodies and conjugated sulphates. These substances are not thrown off by the skin, or by the lungs, and must all be eliminated through the kidneys. They are the result of the oxidation and the breaking down of the proteins of the body. If the kidneys do not throw these off, the result is Uremic Poisoning, and the dietetic treatment must be to cause a free action of the kidneys by the use of diuretics. Of these the citrous fruits, (lemons, oranges, limes, etc.,) are the best; they neutralize acids and produce an alkalinity of the blood. They should be used freely. Meats, eggs and legumes should be eliminated from the diet. A free drinking of water, milk with limewater, cereals, buttermilk, kumyss, barley water, toast water, lemonade, orangeade, vegetables and fruit should constitute the diet. Exercise and free breathing of fresh air are imperative. All food should be thoroughly masticated. * * * * * [Sidenote: Excess of Uric Acid] An excess of uric acid may not always cause uremic poisoning, but it indicates an excess of protein in the system above the amount eliminated by the kidneys and the skin. This excess is often the cause of chronic ailments, such as bronchitis, asthma, hay-fever, severe nerve depression, gout, rheumatism, neuralgia, tonsilitis, grippe, influenza, colds, etc. The natural relief is to control the diet, supplying less protein and to increase the elimination through a free action of the kidneys, of the pores of the skin, and of the lungs. Systematic exercise, deep breathing, a copious drinking of water and fresh air day and night, are the best reliefs. One may either eliminate the proteins from the diet, or may cut down the entire quantity of food, and, by exercise, breathing, a freedom of the pores of the skin and a free drinking of water, so as to create an activity of the kidneys, may continuously eliminate more uric acid than is consumed in the food. The regulation of the quantity of the food, rather than the cutting down of the proteins and the feeding of a larger proportion of starches, is the course pursued where one is inclined to an excess of uric acid and still has an excess of fat. In case of an excess of uric acid in thin persons, such proteins food as meat and eggs may be eliminated and the diet consist almost wholly of carbohydrates and fats. The diet is the same as that given above for _Gout_. * * * * * [Sidenote: Obesity] All diets for obesity must be prescribed for the individual condition. A large number of the obese are afflicted with rheumatism, sluggish livers, sluggish action of the intestines and weak nerves, and the diet must be governed accordingly.[12]