Week 1 - DRV & Alcohol Flashcards
EAR
estimated average requirement
meet 50% of the whole population - assuming normal distribution
LRNI
Lower reference nutrient intake - 2 SD below from the normal, meet 2.5% of the whole populations needs
RNI
reference nutrient intake - 2 SD above the normal and meets 97.5% of the whole populations needs
Nutrient - macro/micro
Nutrient is something that gives essential nourishment to function
macro - carb, protein, fat, alcohol
micro - vitamins & minerals
nutrient requirement equation
nutrient requirement = metabolic demand / efficiency
* not everyone has the same
Safe intake
Intake considered fine for most people but not too high that could cause adverse effects
Used for nutrients/minerals where there is insufficient information
DRV - important notes
Dietary reference value
- apply to healthy people
- doesn’t apply to those with disease or metabolic abnormalities
- assumes all other nutrient requirements are met
- knows that not 100% of nutrient gets absorbed (exception made for Iron, this is accounted for)
Data to determine DRV’s
- Observational - look at populations with deficiency or excess
- Balance studies - intakes known and match losses
- Physiological estimates - to meet needs of growth tissue e.g. milk production in lactate breastfeeding
- Functional studies - intake associated with optimal functioning
- Clinical studies - e.g. how to cure vitamin D deficiency
Defining adequacy
- Have safe upper limits
- Prevent deficiency
- Optimise body stores
DRV - Protein
EAR - 0.6g per kg of body weight per day
RNI - 0.75g per kg of body weight per day
- more required for infants, children, pregnant and breast feeding women
DRV - Energy
Derived from fat, carb, protein and (alcohol)
EAR - assumes normal distribution, 50% of population will require less, and 50% will require more
- Assumes intake matches appetite, based on total energy expenditure (TEE)
Total energy expenditure (TEE)
= basal metabolic rate (BMR) x physical activity levels (PAL)
– females 19-50y EAR = 8.1 MJ /1940 kcal
[Based on 60kg & PAL = 1.4 (inactive)]
– males 19-50y EAR = 10.6 MJ /2550 kcal
[Based on 74kg & PAL = 1.4 (inactive)]
DRV - Fat/ Carbs/ Sugars
Not DRVs set - no known deficiencies or toxicities
There are some essential fatty acids
Assumes 5% energy comes from alcohol
Assumes 15% comes from protein
DRV limitations
Limited to certain groups .e.g Men Some groups we don't know much about e.g. Children Data errors e.g self-reported data Some nutrients there is little known Needs to be updated 10-15yrs Requirements are only a best guess Safety margins can vary across countries
Ethanol
- Structurally like carb
- metabolically like fatty acid
- High energy content
- ‘Empty calories’ because no nutrients except folate in beer
- Not essential because no essential nutrients
- In UK it’s assumed that 5% energy comes from alcohol
