Symptoms can be caused by extremes of either yin or yang. In order to neutralize or offset a particular symptom, we use foods that have the a quality of energy that is opposite to that of the symptom. If the symptom is caused by too much yang, we supply the body with yin. When a symptom is caused by excess yin, we need to supply yang. Constipation offers an example of this principle.
Constipation can result from either an excess of yin or yang in the diet.
Yang constipation is caused by the repeated intake of meat, cheese, eggs, chicken, and other forms of animal food, and an insufficient intake of grains, vegetables, and other plant foods containing fiber. It occurs when the intestines become overly tight and contracted. To relieve that symptom, we use foods with an opposite, or more yin energy, such as kanten, lightly steamed greens, grated raw daikon, or vegetables that have been lightly sauteed in oil. Yin constipation occurs when the intestines become loose, weak, and stagnant because of too much sugar, chocolate, alcohol, spices, ice cream, or soft drinks. Therefore, according to the principles stated above, if we wish to strengthen the liver and gallbladder, we choose foods that have a slightly more yin, or expansive quality of energy.