nutrition Flashcards
what are the immediate causes of major dental diseases?
diet, plaque and smoking
what are many diseases linked to?
oral inflammation
what can be assessed to look for diseases in the body?
the mouth
- corners
- tongue
- palate
- teeth
why do we see changes more easily in the mouth?
- oral epithelium has rapid turnover
- however healthy epithelium acts as a barrier to toxins
what is primary nutritional deficiency?
- inadequate selection of foods
- age, income, education
what is secondary nutritional deficiency?
Systemic disorder interfering with
Ingestion
Digestion
Absorption
Transport
Use of nutrients
which nutrients are required?
calcium, phosphorus, vitamins A,C and D, protein
which nutrients are bad?
CHO, sweet sticky foods etc.
what does nutrition mean?
describes the processes whereby cellular organelles, cells, tissues, organs and the body as a whole obtain and use necessary substances obtained from food (nutrients) to maintain structural and functional integrity
what are the 5 basic steps of dietary assessment?
- report
- identify food
- quantify
- frequency
- calculate intake
what are dietary allowances?
- quantitative amounts essential micronutrients, energy and protein to prevent deficiencies
- based on requirements
what are dietary goals?
- quantified national targets for selected macronutrients and certain micronutrients aimed at preventing long term disease
what are dietary guidelines?
- targeted at individuals- advisory statements for the whole population to promote overall nutritional well being and reduce diet related conditions
- broad targets, qualitative or quantitative
how many kcal should we eat on average?
women 2000kcal
men 2500 kcal
what is the SACN?
an advisory committee of independent experts that provide advice to government agencies and departments in public health
what is optimal nutrition?
the amount of a nutrient that:
- prevents deficiency symptoms
- optimises stores in the body
- optimises biochemical or physiological function
- optimises a risk factor for a disease
- minimises incidence of a disease
definition of requirement by panel
- need to replenish lost nutrients from diet/stores
what is the criteria or adequacy?
- needed to maintain a given circulating level, enzyme saturation or tissue concentration
- associated with the absence of any signs of a deficiency disease
- needed to maintain balance
- needed to cure a clinical deficiency
- associated with an appropriate biological marker of nutritional adequacy
DRV meaning
dietary reference values
EAR
estimated average requirement- of a nutrient which will meet the need of 1/2 the population
RNI
reference nutrient intake
- one above EAR which will meet needs of most people
- one below EAR which will meet needs of few people
safe intake
a level of nutrient at which there is no risk of deficiency but below a level where there is risk of undesirable effects
what are the categories in which DRV are adjusted for?
- Age and Gender
- Breast/formula fed infants
- Body Weight e.g. energy, protein
- Physical activity level (PAL) e.g. energy
- Pregnancy and lactation
- Elderly
who uses DRV?
- governments & NGOs in provision of food aid, food supplements and rationing
- food industry in development & marketing of new food products
- caterers in devising nutritionally adequate menus
- nutrition labelling - DRVs used to derive guideline daily amounts (GDAs) used on nutrition labels
- developing dietary guidelines & goals
- researchers & health professional in assessing the adequacy of diets of groups (or individuals but cautiously)
what are the 4 classes of nutrients?
macronutrients
micronutrients
water
alcohol
what is included within macronutrients?
carbs
proteins
fats and oils (lipids)
what is included within micronutrients?
minerals
vitamins
what is the chemical energy from nutrition used for?
electrical energy (maintain ionic gradients)
chemical energy (e.g. protein synthesis)
mechanical energy (e.g. muscle contraction)
heat energy (maintain body temperature)
what is energy measured in?
kilojoules (kj) - kilocals is the old system
what part of nutrition does energy come from?
macronutrients and alcohol
what is energy density?
energy a food contains per gram
is fat, carbohydrate or protein more energy dense?
fat
how is the total energy content of food calculated?
burn food and measure the heat released
how is the total energy content of food calculated?
burn food and measure the heat released
how is the total energy content of food calculated?
burn food and measure the heat released
how is the total energy content of food calculated?
burn food and measure the heat released
what is a low energy density food?
food with fewer calories per gram
what energy density do foods with high fat and low water content have?
high energy density
what are the three components which make up total energy expenditure?
- basal metabolic rate (60-75%)
- physical activity (10-40% but can reach 70%)
- thermogenesis (10-20%)
- additional requirement for growth
what is basal metabolic rate?
Vital body functions eg maintaining electrochemical gradient, cell and protein turnover, lung and heart function etc.
what is thermogenesis?
Including that though metabolising food (diet induced), throughmuscle action (dynamic and isometric) and through climate (coldinduced)
when is energy balance achieved?
energy intake= energy output
when is a positive energy balance desirable?
during growth, pregnancy and lactation
when is a negative energy balance desirable?
over medium term, fat stores will be used for energy and over long term, protein will also be used
(can lead to health problems)
what factors affect energy requirements?
- body size (bigger=more energy needed)
- age (more needed during growth)
- activity
- pregnancy/lactation
- disease/trauma/treatments (fever/stress increase metabolic rate, medications can increase/decrease rate)
what were used to set DRV?
Calorimetry
- Metabolic chamber: expensive and artificial
Indirect calorimetry
- O2/CO2 measurements: methodological limitations
Doubly labelled water
- Allows measurement without constraint
Energy intake data from surveys
what do DRV surveys assume?
Assumes the general population is in energy balance
Assumes intake data is accurate
why do we use estimated average requirement over reference nutrient intake?
health consequences due to over consumption
what makes up carbohydrates?
carbon, hydrogen and oxygen
how much of total energy intake do carbohydrates make up?
40-80%
what are the types of carbohydrates?
sugars and polysaccharides
what is a monosaccharide?
single sugar molecule
what is a disaccharide?
two sugar molecule
what are polyols?
sugar alcohols
what are examples of polysaccharides?
starch
glycogen
what is sucrose made of?
glucose and fructose (broken down by sucrase)
what is lactose made of?
glucose and galactose (broken down by lactase)
what is maltose made of?
glucose and glucose (broken down by maltase)
what is used in diabetic products?
sugar alcohols
what are the types of sugars?
extrinsic eg milk products
intrinsic eg fruit and veg
what is the difference between free sugars and added sugars?
includes all monosaccharides/disaccharides added to foods/beverages by the manufacturer/cook/consumer, plus sugars naturally present in honey/syrups/unsweetened fruit juices and fruit juice concentrates
- outside the cell (not fruit end veg etc)
what is the WHO guidelines for free sugar intake?
intake of free sugars should provide ≤10% of energy intake
what is starch?
storage carbohydrate
- insoluble in water
- cooking makes starch digestible
what are the two main types of starch?
amylose (unbranched)
amylopectin (highly branched)
what happens to food not digested in the small intestine?
It is fermented by the colonic microflora to short chain fatty acids and gases
Acetic, propionic and butyric acid
All have some health benefits and act as an energy source.
what is a prebiotic?
undigestible carbohydrate which stimulate gut healthy bacteria production
describe oligosaccharides as dietary fibre
- insulin and oligofructose
- not hydrolysed/absorbed in upper gastrointestinal tract
- reach the colon and are fermented by microflora of the colon leading to selective stimulation of the growth of the bifidobateria popultion
- named prebiotics
what are the three categories within dietary fibre?
Non-starch Polysaccharides
- Cellulose and non-cellulose polysaccharides (pectins, glucans, gums, arabinogalactans, mucilages, etc).
Resistant Oligosaccahraides
- FOS and GOS
Resistant Starch…
is fibre easily digested?
NO
which carbohydrates are not digestible?
cellulose
hemicellulose
oligosaccharides
modified starch
resistance starch
what is the best index of dietary fibre?
non-starch polysaccharide (NSP)
- also known as dietary fibre/roughage