UNIT 2 Flashcards
is used to define the terms describing the number of nutrients we consume, such as recommendation, requirement, dietary allowances, adequate intake, upper limits, tolerance, estimation, average requirements, and so on
dietary reference standards
there are four sets of reference data, collectively called Dietary Reference Intakes or DRIs these are the following:
- Estimated Average Requirement (EAR)
- Recommended Dietary Allowance (RDA)
- Adequate Intake (AI)
- Tolerable Upper Intake Level (UL)
covers the period from birth through 12 months of age and is divided into two 6-month intervals.
Infancy
To derive the AI value for infants ages 0 through 6 months, the mean intake of a nutrient was calculated based on the average concentration of the nutrient from 2 through 6 months of lactation with use of consensus values for the nutrient estimated average volume of milk intake of 0.78 L/day as reported from studies of full-term infants by test weighing, a procedure in which the infant is weighed before and after each feeding, the computed value represents the mean. It is expected that infants will consume increased volumes of human milk as they grow.
Ages 0 - 6 Months
The basis of the AI values derived for this age category was the sum of the specific nutrient provided by 0.6 L/day of human milk, which is the average volume of milk in this age, and those provided by the usual intakes of complementary weaning foods consumed by infants of this age.
Ages 7 - 12 Months
The higher velocity of growth in height during ages 1 through 3 years compared with ages 4 through 5 years provides a biological basis for dividing this period. Data are sparse for nutrient adequacy indicators to derive DRIs for these early years of life.
Toddlers: Ages 1 - 3 Years
Significant biological changes in the velocity of growth and changing endocrine status occur during ages 4 through 8 or 9 years (the latter depending on the onset of puberty in each gender). A reasonable amount of data is available on nutrient intake and various criteria for adequacy (such as nutrient balance measured in young children aged 5 through 7 years) that can be used as the basis for the EARs and AIs for this life stage group.
School Age: 4 – 8 Years
The mean age of onset of breast development (Tanner Stage 2) for girls is ten years old; this is a physical marker for the beginning of increased estrogen secretion. The onset of the growth spurt in girls begins before the onset of breast development.
Puberty/Adolescence: Ages 9 - 13 Years and 14 - 18 Years
The recognition of the possible value of higher nutrient intakes during early adulthood on achieving the optimal genetic potential for peak bone mass was the reason for dividing adulthood into ages 19 through 30 years and 31 through 50 years. Moreover, mean energy expenditure decreases from 19 through 50 years, and the need for nutrients related to energy metabolism may also decrease.
Young Adulthood and Middle Ages: Ages 19 - 30 Years and 31 - 50 Years
years spans active work years for most adults. After age 70, people of the same age increasingly display variability in physiological functioning and physical activity. A comparison of people over age 70 years who are the same chronological age may demonstrate a 15- to 20-year age-related difference in the level of reserve capacity and functioning. This is demonstrated by age-related declines in nutrient absorption and renal function.
Adulthood and Older Adults: Ages 51 Through 70 Years and Over 70 Years
may be subdivided because of the many physiological changes and changes in nutrient needs during these life stages. In setting EARs and AIs for these life stages, however, consideration is given to adaptations to increased nutrient demand, such as increased absorption and more significant conservation of many nutrients. Moreover, nutrients may undergo net losses due to physiological mechanisms regardless of the nutrient intake, such as seen with calcium in lactation
Pregnancy and Lactation
is the intake that meets the estimated nutrient needs of half of the individuals in a specific group.
Estimated Average Requirement (EAR)
This figure is to be used as the basis for developing the RDA. It is to be used by nutrition policymakers in evaluating the adequacy of nutrient intakes of the group and planning how much the group should consume
Estimated Average Requirement (EAR)
Energy requirements fall with advancing age. This is due to a decrease in basal metabolic rate and often decreased levels of physical activity. The ability to synthesis vitamin D by the skin decreases with age.
- Age:
Women have a higher proportion of body fat compared to men. However, women consume fewer kilojoules per kilogram lean mass and burn fat more preferentially during exercise than men. During gestation, women store even more enormous amounts of fat that cannot be solely attributed to increased energy intake.
- Sex
