system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 Why do different types of preparation of the same food can result in different nutritional values?

For example: 
Frying vs boiling an egg
Eating fruits straight up vs drinking a smoothie made by blending just fruits

Provided nothing is added (like oil, sugar, salt etc etc)
gpt
If nothing is added, most of the content remains the same generally, unless cooked.

Cooking changes the molecular structure of the food, mainly breaking down complex chains of compounds into simpler and easy to digest forms. It also changes the molecular structure of the compounds and makes some things like vitamins lose their structure.

The method of coction dictates how much heat and therefore change a molecule will receive. In general terms the more heat is received by the food the easier will be for us to digest its base molecules like aminoacids, carbohidrates, etc., but it will make things like vitamins not consumable.