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Nutrition is the process by which a human being takes in and utilizes substances that are not synthesized in sufficient amounts in the body and therefore must be supplied by the diet.
These are carbohydrates, lipids, proteins, water, vitamins, and minerals.
Reference
1. http://2012books.lardbucket.org/books/an-introduction-to-nutrition/index.html
https://www.nutrition.org.uk/attachments/article/234/Nutrition%20Requirements_Revised%20Oct%202016.pdf