By Nutrition Expert – Trupti Gurav,Mumbai
Eating nutritious food can improve the energy levels in your body and helps you to keep it healthy. But the wrong methods of cooking can impact the whole nutrition contain in vegetable or fruit.
We try different methods of cooking- boiling, sauteing, frying, grilling etc. Everyone has their own unique way of preparing a particular dish.
It’s important to select the right cooking method to maximize the nutritional quality of your meal.
However, there is no perfect cooking method that retains all nutrients. 
While eating nutritious food can improve our health and energy levels, the way it is cooked can impact the nutritional value in it.
This study was published by Nimish Mol Stephen; J Food Sci Technol. 2010 Mar, concluded that; boiling fish was shown to preserve omega-3 fatty acid content significantly more than frying or microwaving.
Another study was published by Gao-feng Yuan J Zhejiang Univ Sci B, 2009 Aug; 10 concluded that; boiling reduces vitamin C content more than any other cooking method. Broccoli, spinach, and lettuce may lose up to 50% or more of their vitamin C when boiled. 
Over all while water-based cooking methods cause the greatest losses of water-soluble vitamins, they have very little effect on omega-3 fats. 
This study was published by Adriana D.T.Fabbri , in International Journal of Gastronomy and Food Science , April 2016, Concluded that; cooking, boiling, heating, soaking, backing, steaming, chopping all the steps included before vegetables and legumes consumption can affect directly their nutrition quality.
Overcooked veggies are better than no veggies at all but quick cooking will maximize nutrients. Take advantage of as many vitamins as possible by following these tips: 
- When peeling the skin of vegetables do peel as thinly as possible. The nutrients in vegetables and fruits are concentrated just below the skin, so peeling before boiling increases the loss of Vitamin C, Folic Acid and other B vitamins. Peel only when absolutely necessary.
- Root vegetables should be boiled with skins on and then peeled after boiling. This helps the nutrients to migrate to the centre of the vegetables, helping better retention of its nutrients. Do eat with skin on whenever possible.
- Do not cut vegetables into very small cubes as the surface area of vegetable increases that comes in contact with oxygen, destroying more nutrients.
- Cut food after — rather than before — cooking, if possible. When food is cooked whole, less of it is exposed to heat and water.
- Don’t soak vegetables in water to prevent discoloration- If you soak vegetables in water for a long period then, almost 40% of soluble vitamins and minerals are lost. If you really have to soak them, use the remaining water as vegetable stock, or to knead the dough, prepare soups and gravies.
- Salads should be prepared just before serving and should be served in closed dishes to avoid excessive exposure to air.
- Do not throw away the excess water drained after boiling rice or vegetables. When preparing cottage cheese, the water left over after curdling (called whey)-is extremely rich in good quality proteins and vitamins and should be used up in preparing gravies, kneading dough or simply had as a refreshing drink after flavouring with lemon juice, salt and pepper.
- Cook vegetables in smaller amounts of water to reduce the loss of vitamin C and B vitamins.
- Do not keep milk open or exposed to light, as a considerable destruction of riboflavin can occur.
- It is preferable to cook vegetables in a minimum amount of water keeping the vessel covered and to consume it as soon as possible. Reheating cooked vegetables further destroys vitamins.
- Baking soda makes cooking water alkaline and thus helps retain the colour of vegetables as well as speed up the cooking process, but it destroys thiamine and vitamin C.
- Deep frying and heating for a long time or heating at a high temperature should be avoided during cooking. If food material is heated above 700 C for a long duration, proteins become hard and coagulated. In this form, they are not easily absorbed by the body. Thus, overcooking results in loss of precious nutrients.
- Choose steaming over boiling.
- Use a pressure cooker when possible.
- When cooking meat, poultry, and fish, use the shortest cooking time needed for safe consumption.
- Reheating food destroys the chemical structure of nutrients and vitamins. In fact, cooked vegetables that are reheated after being kept in the refrigerator for two or three days lose more than half their vitamin C.
- Baking soda makes cooking water alkaline and thus helps retain the colour of vegetables as well as speed up the cooking process, but it destroys vitamin C content of the veggies.
- Eating freshly cooked food is preferable because the depletion of nutrients could be slowed down. It is a good idea to eat within 4 hours of cooking your food.
For best results, cook:
- For shorter periods of time
- At lower temperatures
- With less water
- And minimal waste of by products