Any ‘’diet’’ that fails to provide nutritional benefits or predisposes an individual to any type of disease condition is termed as an ‘’unhealthy diet’’.
An unhealthy diet encompasses incompatible diet and dietary mannerism. According to ancient Ayurvedic literature, incompatible diet ( Viruddha Ahara ) is defined as the food constituents in any preparation that are consumed in a wrong combination, are under processed or overprocessed, are not consumed in proper quantities, or are consumed at an incorrect period/hour of the day or in the wrong season.
Certain healthy foods when combined and consumed might be incompatible and cause severe disease condition including skin diseased in charak Samhita and ancient Ayurvedic literature, it is stated that milk should be avoided along with a diet that includes all sour foods such as fermented food item (Eg. Idli and dhokla) fruits ( example Amla and pineapple and pomegranate) curd, buttermilk, and fish.
Diet practices have evolved with time however, the basic principle followed in the in olden days hold Good even today.