What are the nutritional requirement of an adult and elderly?

First of all, you need to know that a "nutritional requirement" is the smallest amount of a nutrient (proteins, carbohydrates, lipids, minerals, vitamins, and water) that maintains a defined level of nutritional health. The requirement for each nutrient varies to some degree from person to person, and factors like age, sex, general health status, physical activity level, and use of medications are factors that influence your nutrient requirements.

Another key point to remember is that simply obtaining the "required" amounts of nutrients does not result in optimal nutritional status. Some nutrients are stored in the body, some are not. Your body uses the stored nutrients much like you use your savings account to manage your money. Those essential vitamins, minerals, fats and amino acids not synthesized by the body must come from directly from the diet, and may or may not be stored.


What is the difference between the "Estimated Average Requirement (EAR)" and the "Recommended Dietary Allowance (RDA)"? EAR = amount of nutrient that should meet the needs of 50% of the healthy people in a life/stage/gender group. RDA = amount of nutrient that should meet the needs of about 98% of healthy people in a life/stage/gender group.


By now, I think you should be getting the idea that there is no simple answer to your question.


Rather, I would direct your attention to the Food and Nutrition Board (FNB) that is composed of a group of nutritional scientists who develop daily recommended intakes of nutrients.


The home page of the USDA National Agricultural Library Food and Nutrition Information Center is:
http://fnic.nal.usda.gov/nal_display/index.php?info_center=4&tax_level=1&tax_subject=242