Nutrition overview
Nutrition: the biochemical and physiological process by which an organism uses food to support its life
the process of nourishing the body
Nutrients: the constituents of food necessary to sustain the normal functions of the body.
some provide energy
most help to build cells and tissues, and/or regulate body processes
no single food supplies all the nutrients the body needs to function
Diet: the customary amount and kind of food and drink a person takes in day to day.
All energy is provided by the three classes of macro-nutrients (intake needed is larger):
fats
carbohydrates
protein
Nutrients needed in lesser amounts are called micro-nutrients
They include:
vitamins
minerals
essential fatty acids
essential amino acids
Calorie: unit of energy, the amount of heat necessary to raise the temperature of 1kg of water 1°C
Fats: 9 cal/g
Carbohydrate and protein: 4 cal/g
Dietary Reference Intakes (DRI): estimates of the amounts of nutrients required to prevent deficiencies and maintain optimal health and growth.
Th DRI establishes upper limit on the consumption of some nutrients, unlike the Recommended Dietary Allowances (RDA).
The DRI consists of 4 dietary reference standards for the intake of nutrients designated for specific age groups, gender, and physiologic states.
Estimated Average Requirement
Recommended Dietary Allowance
Adequate Intake
Tolerable Upper Intake Level
The average daily nutrient intake level estimated to meet the requirement of one half of the healthy individuals in a particular life stage (age) and gender group.
The average daily nutrient intake level that is sufficient to meet the requirement of nearly all (97% - 98%) individuals in a particular life stage and gender group.
RDC is not the minimal requirement for healthy individuals, but rather it provides a margin of safety for most individuals
the EAR serves as the foundation for setting the RDA
RDA = EAR + 2 SD (standard deviation)
An Adequate Intake (AI) is set instead of an RDA if there is insufficient scientific evidence available to calculate an EAR of RDA.
based on estimates of nutrient intake by a group/s of apparently healthy people
The highest average daily intake level that is likely to pose no risk of adverse health effects to almost all individuals in the general population.
as intake increases above the UL, the potential risk of adverse effects may increase
useful because of the increased availability of fortified foods and the increased use of dietary supplements
for some nutrients, there may be insufficient data on which to develop a UL
most nutrients have a set DRI
usually a nutrient has an EAR and a corresponding RDA
most are set by age and gender, and are influenced by special factors (e.g. pregnancy and lactation in women)
when data are not sufficient to estimate an EAR (or RDA), and AI is designed
intakes at or above the RDA can be considered adequate
intakes above the AI can be considered adequate
intakes between the UL and the RDA can be considered to have no risk for adverse effects
intakes over the UL show risk for adverse effects
the DRI does not include any special needs of the sick, it is designed to meet the nutritional needs of the healthy
Nutrition: the biochemical and physiological process by which an organism uses food to support its life
the process of nourishing the body
Nutrients: the constituents of food necessary to sustain the normal functions of the body.
some provide energy
most help to build cells and tissues, and/or regulate body processes
no single food supplies all the nutrients the body needs to function
Diet: the customary amount and kind of food and drink a person takes in day to day.
All energy is provided by the three classes of macro-nutrients (intake needed is larger):
fats
carbohydrates
protein
Nutrients needed in lesser amounts are called micro-nutrients
They include:
vitamins
minerals
essential fatty acids
essential amino acids
Calorie: unit of energy, the amount of heat necessary to raise the temperature of 1kg of water 1°C
Fats: 9 cal/g
Carbohydrate and protein: 4 cal/g
Dietary Reference Intakes (DRI): estimates of the amounts of nutrients required to prevent deficiencies and maintain optimal health and growth.
Th DRI establishes upper limit on the consumption of some nutrients, unlike the Recommended Dietary Allowances (RDA).
The DRI consists of 4 dietary reference standards for the intake of nutrients designated for specific age groups, gender, and physiologic states.
Estimated Average Requirement
Recommended Dietary Allowance
Adequate Intake
Tolerable Upper Intake Level
The average daily nutrient intake level estimated to meet the requirement of one half of the healthy individuals in a particular life stage (age) and gender group.
The average daily nutrient intake level that is sufficient to meet the requirement of nearly all (97% - 98%) individuals in a particular life stage and gender group.
RDC is not the minimal requirement for healthy individuals, but rather it provides a margin of safety for most individuals
the EAR serves as the foundation for setting the RDA
RDA = EAR + 2 SD (standard deviation)
An Adequate Intake (AI) is set instead of an RDA if there is insufficient scientific evidence available to calculate an EAR of RDA.
based on estimates of nutrient intake by a group/s of apparently healthy people
The highest average daily intake level that is likely to pose no risk of adverse health effects to almost all individuals in the general population.
as intake increases above the UL, the potential risk of adverse effects may increase
useful because of the increased availability of fortified foods and the increased use of dietary supplements
for some nutrients, there may be insufficient data on which to develop a UL
most nutrients have a set DRI
usually a nutrient has an EAR and a corresponding RDA
most are set by age and gender, and are influenced by special factors (e.g. pregnancy and lactation in women)
when data are not sufficient to estimate an EAR (or RDA), and AI is designed
intakes at or above the RDA can be considered adequate
intakes above the AI can be considered adequate
intakes between the UL and the RDA can be considered to have no risk for adverse effects
intakes over the UL show risk for adverse effects
the DRI does not include any special needs of the sick, it is designed to meet the nutritional needs of the healthy
