nutrition and health Flashcards
examples of macronutrients
lipids, carbohydrates, proteins and alcohol
examples of micronutrients and how much is needed
vitamins
essential minerals, amino acids and fatty acids
small amounts - g, mg, micrograms per day
what do requirements vary depending on…
age
gender
activity levels
what’s the requirement for a nutrient
amount needed to prevent deficiency
(societies expect more than that)
storage for times of low/no intake
which company decides the recommended daily intakes?
- food standards agency
- renamed to: committee of medical aspects of food policy (COMA)
- dietary referene values for Food Energy and Nutritents for the United Kingdom
how are recommended intakes experimentally worked out?
- look at intake of groups with and without a deficiency
- intakes that CURE the clinical deficiency (minimum)
- Intakes associated with marker of nutritional adequacy (enzyme saturation, tissue concentration) (minimum + safety margin for storage)
how is EAR calculated?
normal distribution curve - the middle
How is RNI (referent nutrient intake) calculated
on the normal distribution curve, go 2 standard deviations above EAR
-satisfies needs of 95% population
what do 3 standard deviations from median on a normal distribution curve represent?
99.7% total
What is EAR
Estimated Average Requirement
The notional mean requirement of a nutrient (for a group of healthy individuals in a population); 50%
What is RNI
Reference Nutrient Intake
Two standard deviations above the EAR, sufficient of a nutrient to meet the needs of most of the population; (95%)
(Formerly termed: Recommended Daily Allowance.)
what LRNI
Lower Reference Nutrient Intake (LRNI)
Two standard deviations below the EAR; intakes of a nutrient below this level are almost certainly inadequate for most individuals.
provide sufficient for 5%
what’s the EAR, RNI and LRNI for vitamin C per day (ascorbic acid)
EAR 25mg
RNI 40mg
LRNI 10mg
why do we not use normal distribution for energy requirement
- get fat
- energy: advise the Estimated avgrequirement
why are EARs and RNIs important (current uses)
- nutritional programmes for different types of people
- formulations for babies schools
- clinical nutrition i.e. patients on enteral or parental nutrition
how do we know how much of a substance we are taking?
food tables
McCance and Widdowson’s
The chemical composition of foods
1st edition 1946, 6th 2002
the mean content of what substances can be worked out from food analysis
available energy, • water, • protein, • fat, • carbohydrate, • alcohol, • vitamins, • minerals, • dietary fibre
why are food tables still useful if they are not accurate?
-e.g in the analysis of an individual’s nutrient and energy intakes
In formulation of diets where certain foods must be avoided
-e.g diets for diabetics, people with high cholesterol , on dialysis etc
where in the world is undernutrition prevalent
developing
South Asia, sub-Saharan Africa, parts of South America
what deficiencies are seen in the developed world
- Usually specific deficiencies
* i.e. proteins, vitamins, minerals
who are the main groups of people affected by deficiencies
- Elderly,at home on their own or in institutions
- Young people on junk food
- Some Asian women and children in traditional clothes
- Slimmers and people on fad diets
- Cancer and AIDS patients
- People with eating disorders
- Up to 40% of hospitalised patients
formula for BMI
what is ideal BMI
kg/(height in m)^2
18.5 - 24.9
what are the obesity statistics in the UK
2/3 of adults are obese or overweight
of these: 22% men and 23% women are obese
stats have tripled in past 20years
global obeisity % in 1980 and 2008?
23% to 34%
