2e Health and Social Behaviour Flashcards
What is the role of public health in nutrition?
Public health nutrition involves studying the relationship between dietary intake and disease (nutritional epidemiology) and applying the knowledge gained to help prevent disease in the population (nutrition intervention).
Dietetics is the application of nutritional knowledge particularly tailored to individual needs. It generally involves the use of diet in the treatment and management of disease.
What is the The Eatwell Plate?
Designed by the Food Standards Agency to make healthy eating choices easier to understand for individuals (http://www.food.gov.uk).
The plate is a visual representation of the five types and proportions of food people need to maintain a healthy and balanced diet. The five types are broken down into the following categories:
Fruit and vegetables
Bread, rice, pasta, potatoes, and any other starchy foods
Milk and dairy foods
Meat, fish, eggs, beans, and any other non-dairy sources of protein
Foods and drinks high in fat and/or sugar.
Food that represent the largest groups/proportions in the Eatwell Plate should be eaten most often, and food from the smallest groups/proportions should be eaten least often.
What is national surveillance in relation to nutrition?
Nutritional surveillance involves the routine collection and collation of data which inform us about the nature and causes of nutritionally related diseases.
Initially, these were diseases arising from nutritional deficiencies (e.g. anaemia, rickets, and osteoporosis) but they now include a whole range of conditions (e.g. obesity, hypertension, cancers, coronary heart disease, and dental caries).
How is national surveillance for nutrition done in the UK?
National food productions, household expenditure on food, household studies of food purchases and consumption and occasionally studies of individual
consumption contribute to the Food and Agriculture Organisation’s data on national food balance sheets.
This is a surveillance system that links dietary and health surveillance (using indices of health such as weight, blood pressure, serum
cholesterol and anaemia) allows more effective evaluation of the dietary contributors to diseases such as obesity, diabetes, hypertension and cardiovascular disease.
How is national surveillance for nutrition done in the UK?
National food productions, household expenditure on food, household studies of food purchases and consumption and occasionally studies of individual
consumption contribute to the Food and Agriculture Organisation’s data on national food balance sheets.
This is a surveillance system that links dietary and health surveillance (using indices of health such as weight, blood pressure, serum cholesterol and anaemia) and allows evaluation of the dietary contributors to diseases such as obesity, diabetes, hypertension and cardiovascular disease.
In the UK, the National Diet and Nutrition Survey (see Markers of nutritional status, nutrition and food) links diet with indices of health. It was established to compare current intakes of nutrients with the various Dietary Reference Values (DRVs) to assess where problems exist in the population (e.g. high salt intake and low consumption of fruit and vegetables) and to assist with informing government policy.
What are the short and long term markers that can be used for nutritional intake?
Short:
High intake of sugary foods – Increased dental caries
High intake of salt – increased blood pressure
Long Term:
Lack of fruit and vegetable intake – colon cancer
High and prolonged intake of alcohol – colon cancer
Lack of breastfeeding – breast cancer
Central obesity – type 2 diabetes
Lack of dietary calcium – osteoporosis
What is malnutrition?
A lack of proper nutrition is caused by not having enough to eat, not eating enough of the right things, or being unable to use the food that one does eat. Note it can include overeating as well as undereating.
What are the risks of over-nutrition?
Obesity
Heart disease
Diabetes
Hypertension.
Excess of certain nutrients (e.g. vitamins and minerals) can result in toxicity over prolonged time periods.
What are the risks of undernutrition?
Loss of weight
Loss of muscle
Increasedq risk of infection
Symptoms - Skin rash, depression, hair loss, tiredness, brittle bones and bleeding gums.
What are the risks of maternal undernutrition?
Intrauterine growth restriction
What are the causes of Intrauterine growth restriction
Maternal undernutrition
Maternal anaemia
Maternal smoking
Maternal infections (especially malaria).
What are the consequences of Intrauterine growth restriction?
Infant mortality and Morbidity
Increases susceptibility to severe malnutrition in childhood
Poor cognitive, mental and physical development.
Increases the risk of chronic diseases in adulthood, Perpetuates an intergenerational cycle of malnutrition, poverty and disease.
What is is the most common nutritional deficiency in the world?
Iron Deficiency Anaemia
Who is most affected by iron deficiency anaemia?
Infants, children, teens and women of childbearing age.
More prevalent in developing countries than in developed countries.
What are the consequences of iron deficiency anaemia during pregnancy?
Increased risk of maternal mortality and morbidity,
Increases risk of foetal morbidity, mortality
Increased risk of low birth weight
What methods can be used to reduce iron deficiency anaemia at a population level?
Iron supplementation (especially in pregnant women);
Iron fortification of certain foods (UK, USA)
Dietary modification to increase the bioavailability of iron.
What are the consequences of iodine deficiency?
Adult Life:
Hypothyroidism
Maternal iodine deficiency:
Cretinism
Stillbirth
Worse infant morbidity and mortality
Postnatal:
Impaired mental development
Who is most affected by iodine deficiency?
Developing countries
What interventions can be used to reduce iodine deficiency?
Iodization of salt (UK)
Iodized oil injections
Iodized oil by mouth.
What are the consequences of Vitamin A deficiency?
Postnatal/Adulthood
Xerophthalmia (a severe drying of the eye surface caused by a malfunction of the tear glands)
Blindness
Maternal:
Night blindness
Increased risk of maternal mortality
In which ways can you reduce vitamin A deficiency at a population level?
Vitamin A supplementation in deficient populations
Dietary changes - Yellow and orange fruit and vegetables
Food fortification, for example, sugar in Guatemala,
Promoting breastfeeding prevents vitamin A deficiency in babies.
In which way can severe protein deficiency present in children?
Kwashiorkor and Marasmus are the two main types. Kwashiorkor is predominantly a protein deficiency, while marasmus is a deficiency of all macronutrients — protein, carbohydrates and fats.
Kwashiorkor
Higher mortality rate
Emaciated appearance except for oedema in ankles, feet, and abdomen.
Can occur in an epidemic form following a measles outbreak.
Marasmus:
Lower mortality rate
Wrinkled and shrunken appearance
Marasmic kwashiorkor:
This may occur if a Marasmic child is overfed with a diet too high in sodium, which causes oedema.
How may undernutrition present in a child?
Severe:
Kwashiorkor
Marasmus
Less severe:
Vitamin Deficiency
Growth failure (body weight and height less than the ideal for their age)
Poor development (deficits in intellectual, cognitive and social behaviour).
How is undernutrition assessed in children?
Weight for age
Height for age
Weight for height
How can individual nutrition status be assessed?
Anthropometry is the means by which body composition can be assessed in living people, method include:
Bodyweight
BMI
Growth charts
Skin fold thickness
Waist circumference
Biochemical and Haematological considerations
How is BMI calculated?
BMI = Weight (kg)/Height squared (meters)
How is BMI interpreted?
<18.5 = underweight
18.5 - 24.9 = healthy weight
25 - 29.9 = overweight
30+= Obese
What are the problems with using BMI?
Does not take into account muscle mass
Not appropriate for children
What are growth charts and how are they interpreted?
The single most important measurement of nutritional status in those under 5 years old. The 3 types of chart include:
* Weight for age
* Height for age
* Weight for height
To be classified with wasting, underweight or stunting, the child must be 2 SD (or more) below the standards compared to internationally accepted reference standards (f international reference populations.
What are the three types of growth chart and what do they each indivudally measure?
Height for Age - Shows linear growth, and can be used to measure for long term growth faltering or stunting.
Weight for Height - Shows proper body proportions and harmony of growth. It is sensitive to acute growth disturbances and detects wasting.
Weight for Age - Used to diagnose underweight children.
What are the limitations of using haematological and biochemical markers for assessing nutrition status?
Change on a daily basis
Compensated for by homeostatic mechanisms
Affected by concurrent disease
Only show depleted levels if there is a severe deficiency
What are the methods for assessing an individual’s diet?
Prospective methods:
Food Frequency and Amount Questionnaires (FAQs)
Food diary
* Household measures
* Weighted inventory
Duplicate Diet Method
Food Checklists
Retrospective methods:
24 hour recall
Diet history
What is the Food Frequency and Amount Questionnaires (FAQs) method of assessing dietary intake and what are its advantages and disadvantages?
Pre-printed lists of foods, which subjects are asked to fill in, indicating the typical frequency of consumption of foods and the average amount.
Advantage
Good for large epidemiological studies
Disadvantages
Questionnaires take a long time to develop
Assess food groups rather than
individual foods (so subjects must know how to classify foods).
What is the food diary method of assessing dietary intake, what are the different types and what are the advantages/disadvantages of each?
There are 2 kinds of food diary – the weighed inventory and the household measures technique:
Weighed inventory:
The most widely used technique.
Subjects keep a record of all food and drink consumed, all weighed prior to consumption.
Advantage:
High accuracy
Disadvantage:
There could be under-reporting.
The household measures technique:
Subjects record their portion sizes in household measures (e.g. cup, bowl, spoonful, etc) instead of weighing foods
Aids (e.g. models or photos) may
improve portion size estimates.
Advantage:
Simplifies the recording process
Disadvantage:
Less precise and thus may lead to misclassification of individuals
What is the duplicate diet method of assessing dietary intake and what are its advantages and disadvantages?
The subject has to weigh and record food consumed, but also weigh and set aside exactly the same portions again. These portions are collected and chemically analysed.
Advantage
Independent of errors associated with food composition tables
Disadvantages:
Expensive
Subjects may fail to set aside exact duplicates.
What is the food checklist method of assessing dietary intake and what are its advantages and disadvantages?
Subjects are given lists of foods commonly consumed by the population under study. The subject then ticks the foods which they have consumed each day, and record the approximate amounts in household measures.
Advantage:
Reduces the amount of recording required
Reduces the amount of time spent processing data.
Disadvantage:
Subjects may fail to record foods not listed (there is a section to add other foods)
What is the 24-hour recall method of assessing dietary intake and what are its advantages and disadvantages?
A trained interviewer asks subjects to recall and describe every item of food and drink consumed over exactly 24 hours. It involves a systematic repetition of open-ended questions, asking subjects to describe amounts in household measures.
Advantages
Quick process to administer (10-15 minutes)
Good compliance
Disadvantage:
A single 24-hour recall can’t classify a subject (it is used for estimating the average intake of groups).
What is the diet history method of assessing dietary intake and what are its advantages and disadvantages?
A diet history is used to assess the usual diet over the recent past. It begins with a 24-hour recall followed by a 2-hour interview to elaborate on this. A trained interviewer asks about the variety and frequency of foods that subjects are likely to eat, assessing differences between weekdays and weekends, and seasonal variation.
Advantage
Highly informative
Special attention can be paid to specific food
Disadvantage
Dependent on the skill of the interviewer
Social bias may lead to over/under-reporting
What are the four dietary reference values (DRV’s) set in the UK?
Estimated Average Requirements (EARs):
An estimate of the average requirement of energy or a nutrient needed by a group of people i.e. approximately 50% of people will require less, and 50% will require more.
Reference Nutrient Intakes (RNIs):
The amount of a nutrient that is enough to ensure that the needs of nearly all a group (97.5%) are being met i.e. the majority will need less.
Lower Reference Nutrient Intakes (LRNIs):
The amount of a nutrient that is enough for only a small number of people in a group who have low requirements (2.5%) i.e. the majority need more.
Safe Intake:
Where there is insufficient evidence to set an EAR, RNI or LRNI. The safe intake is the amount judged to be enough for almost everyone, but below a level that could have undesirable effects.
