The Tamasic or the Static food, according to Yoga Science is those foods whose consumption will bring harmful effect to body and mind. These foods harm the mind consequently creating dullness of mind, a state of unconsciousness, adds impurities to your mind. Tamasic foods harm the body by damaging the physical organs. They are needed when the body is having severe cuts, damages or pain. Tamasic foods help the portion of the body where cuts and damages occurred to get repaired by lowering the physical consciousness of the body. 

Processed and highly processed and synthetic foods should be avoided. These foods according to Yoga Science contains high amount of impurities which affects the provision of nourishment to the body. These foods when consumed cause diseases, adds discomfort, increases obesity of the body. Examples are the various milk products like ghee, butter, soft drinks. Yoga Science says that the main cause of disease is eating unhealthy foods.

Therefore, if you perform regular yoga and want to extract the maximum benefit out of it you should have controlled food habit. Best would be to have only those foods which are permitted by Yoga Science.