A dish ordered in a restaurant and the same dish cooked at home can differ substantially in fat, salt and portion size. The differences come from the constraints a commercial kitchen operates under.
Fat solves several restaurant problems at once
Fat carries aromatic compounds, so a dish with more of it tastes more intensely of its spices. Restaurants compete on flavor impact, and this is the cheapest route to it.
It also stabilizes sauces that must be held in a warmer for hours without splitting or forming a skin, and it produces the visible gloss that makes a plated dish look right.
None of those pressures exist at home, where a dish is cooked and eaten immediately and does not need to survive a service period or photograph well.
Salt is calibrated for a single course
A restaurant dish must taste complete on its own, because it may be the whole meal. Seasoning is therefore set higher than it would be for a component of a multi-dish plate.
An Indian home meal spreads seasoning across several items eaten together, so each individual preparation is milder than its restaurant counterpart by design.
Consistency requires standardization
Restaurants prepare bases in bulk so every plate matches, which means an identical fat and salt baseline goes into dishes that would each be seasoned differently at home.
Bulk preparation also favors ingredients that behave predictably, so cream, butter and prepared pastes displace the more variable fresh ingredients a home cook adjusts around.
Portion size is set by price expectation
The size of a restaurant serving is determined by what a diner considers acceptable value for the price rather than by how much food constitutes a meal.
Because American restaurant portions have grown over decades across all cuisines, the Indian restaurant portion followed, and the amount served in one bowl often exceeds a full home meal's worth of that dish.
Reading the difference correctly
The comparison is not a verdict on either. Restaurant cooking is doing a different job under different constraints, and the resulting food is legitimately different food.
For anyone tracking intake, the practical implication is that nutritional impressions formed from restaurant meals do not transfer to home cooking of the same dishes, and specific dietary questions belong with a dietitian rather than with a menu.