The food we daily take has its effect on our psychology and character. It may be satvik, good and strengthening to the spirit; or destructive of serenity, passion-producing, rajasik; or wholly bad causing deterioration of mind and intellect and increasing inertia, tamasik.
The foods that promote long life and vitality, bodily vigor, health, joy and amiability, which are pleasant to the taste, soft, substantial and satisfying are liked by the satvik natures. Chapter XVII – 8
The passionate desire foods that are bitter, sour, saline, over-hot, pungent, dry and burning are rajasik in nature. These produce sickness, pain and grief. Chapter XVII – 9
Food that is not freshly made, food that has lost its flavor, stale food, and food that has gone putrid, left-over food and food which is filthy, appeal to men of tamasik nature. Chapter XVII – 10
(Source: Book - Pilgrimage to Sabari by K.R.Vaidyanathan)