Religion plays a pivotal role in dietary habits. While Hinduism promotes vegetarianism (stemming from the concept of Ahimsa or non-violence), Islamic influences introduced the art of grilling meats (kebabs), baking (tandoor), and rich gravies using nuts and saffron. Jainism prescribes a strict vegan diet that excludes root vegetables to prevent harm to micro-organisms in the soil.
In the East (Bengal, Odisha), the abundance of rivers makes freshwater fish a staple, often paired with rice. Mustard oil is the primary cooking medium, imparting a pungent, distinct flavor. Conversely, the West (Gujarat, Rajasthan) features arid climates where fresh vegetables are scarce. This necessitated a lifestyle of preservation; hence, the cuisine is heavy on dried lentils (Dal), pickles (Achar), and the use of yogurt/buttermilk to cool the body in the desert heat.
It is a mistake to speak of a singular "Indian food." The Indian lifestyle and cooking traditions change every 100 kilometers. Here is a glimpse of the diversity:
North India (Punjab, Delhi, Uttar Pradesh): Wheat-based. Here you find Tandoori cooking—clay ovens reaching 900°F that cook Naan and Tandoori Chicken in seconds. Dairy is heavy (paneer, cream, butter). The lifestyle is agrarian and robust.
South India (Tamil Nadu, Kerala, Karnataka): Rice-based and fermented. The tropical heat necessitates fermented foods like Dosa and Idli, which preserve the batter and introduce probiotics. Coconut is used extensively—as oil, milk, and grated topping.
West India (Gujarat, Rajasthan): The deserts of Rajasthan created a cuisine that uses milk, buttermilk, and gram flour (besan) extensively due to water scarcity. Gujarat is predominantly vegetarian, famous for the undhiyu (mixed vegetable curry) and the concept of Farsan (snacks).
East India (West Bengal, Odisha): The land of fish and mustard oil. Bengalis worship sweetness (Rasgulla) and bitterness (Shukto). The cooking tradition here uses the Panch Phoron (five-spice blend: fennel, fenugreek, mustard, cumin, nigella).