How cooking method changes calories and nutritional value.

Same ingredients, different cooking method — and the difference can be hundreds of calories per day.
Cooking food changes three things: calorie content (due to added fats or water loss), the content of certain vitamins (they are sensitive to heat and water), and taste, which determines whether you will eat it regularly. Most often, the biggest difference is made not by the food itself but by the fats you add during cooking.
| Method | Calorie change | Vitamin retention | When to choose |
|---|---|---|---|
| Steaming | No change | Best (water-insoluble vitamins remain) | Vegetables, fish, chicken |
| Boiling in water | No change | Some water-soluble vitamins (C, B group) pass into the water | Soups, grains, pasta |
| Baking in the oven | No change (without oil) | Good | Meat, vegetables, fish |
| Stewing | No change | Good (less contact with air) | Dishes with sauce |
| Pan-frying with oil | +50–150 kcal (1–2 tablespoons) | Good | When you need it quickly |
| Deep-frying | +150–400 kcal | Weaker | Rarely — for celebrations |
| Microwave | No change | Good (short time, little water) | For reheating, vegetables |
The numbers depend on the dish and fat content — approximate food calorie content is provided the calorie search.
Do microwaves destroy vitamins? No more than other methods — a short time and little water often mean better retention than long boiling.
Are oven-baked vegetables healthy? Yes, if there is little oil (1 tablespoon for the whole tray) — the taste is more intense and nutritional value is retained.
How much oil is “normal”? If you are losing weight — measure by tablespoons; total cooking with 1–2 tablespoons per day is moderate.