7 - Diet Analysis Flashcards
What are anthropometric measurements?
Measurements or estimates of physical aspects of the body
E.g., height, weight, body composition
Distribution of fat, lean mass and minerals in body
Skinfold thickness, waist/hip circumference/ratio, body density, underwater weighting, bone density
BMI
How can anthropometric measurements be compared?
Measurements can be compared to standards specific for age and gender or previous measurements of the same individual
What is the ‘normal’ range of BMI?
18.5 - 24.9 kg m^-2
How is BMI calculated?
BMI = weight/height^2 in kg m^-2
What is the ‘obese’ range of BMI?
> 30 kg m^-2
What are the disadvantages and advantages of anthropometric measurements?
Disadvantages - certain conditions, genetics and physical activity may affect these values and is not linked to nutrition
Advantages - easy to do and can be compared to available standards
What are biochemical measurements and their disadvantages?
Laboratory analysis of biological samples like blood or urine for biomarkers e.g. specific nutrient
Disadvantages - can be affected by time of day, age, gender, activity patterns, drugs
What does a clinical assessment contain and what are its disadvantages?
Medical history e.g. weight gain/loss, surgeries, medication, previous disease
Unusual symptoms e.g. lack of energy, loss of appetite
Disadvantages - most are not obvious until they become severe
What is does a dietary assessment contain?
Retrospective methods - through recall and questionnaires
Prospective - diet records. Considered one of the most accurate method for dietary assessment
What are the levels of physical activity (PA)?
Sedentary (typical daily living activities (DA))
Low active (DA + 30-60 min moderate activity)
Active (DA + >= 60 min moderate activity)
Very active (DA + >= 60 min moderate + 60 min vigorous or 120 min moderate activity)
What does estimated energy requirement depend on?
Age, sex, physical activity (PA), weight, and height
and growth or life stages e.g. infants, children, adolescents, pregnant and lactating women
What affects energy required to perform physical activity (PA)?
Weight and height
What is a Calorie?
Calorie is unit to measure the heat energy produced by food
Calorie = kcal = kilocalorie (note capital ‘C’)
1 Calorie = 4.2 kJ = energy required to raise the temperature of 1 kg of water from 15° to 16° C
Measured using bomb calorimeter
What are the caloric values of the 3 energy nutrients and alcohol?
Carbohydrate - 4 kcal/g
Protein - 4 kcal/g
Fat - 9 kcal/g
Alcohol - 7 kcal/g
What happens when energy intake is lower/equal/higher compared to EER?
Weight loss/balance/gain
What are the acceptable macronutrient distribution ranges (AMDR)?
Carbohydrate - 45-65%
Fat - 20-35%
Protein - 10-35%
Provides adequate energy and nutrients and reduces risk of chronic diseases
What is retinol activity equivalent (RAE) used for?
RAE is used to account for the different activities of retinol and provitamin A carotenoids
1 IU retinol = 0.3 μg retinol = 0.3 mcg retinol
What is niacin equivalent used for?
Takes into account that tryptophan can be used by the body to make niacin in the presence of vitamin B6 and B12
What is dietary folate requirement used for?
To help account for the differences in absorption of naturally occurring dietary folate and the more bioavailable synthetic folic acid
What is bioavailability?
Amount of nutrients absorbed and used by the body
Folate from fortified foods is more available than natural occurring folate
What are the dietary reference intakes?
EAR - estimated average requirement
RDA - recommended daily allowance
AI - adequate intake
UL - tolerable upper intake
What is EAR?
Estimated average requirement
Nutrient intake levels estimated to meet the requirements of 50% healthy individuals in a group
What is RDA?
Recommended daily allowance
Daily dietary intake levels of essential nutrients sufficient to meet the nutrient requirements of approximately 98% of healthy people
Decreases risk of certain chronic diseases
What is AI?
Adequate intake
Based on less conclusive data = tentative RDAs
% population covered is unknown
Is RDA a minimum requirement?
No. They are recommendations for average daily intakes.
Nutrients goals should be met through diet (not supplements) to obtain other nutrients and prevent UL (tolerable upper limit) risk
How to use DRI to assess dietary intake?
Above RDA - intake probably adequate
Between RDA and EAR - intake possibly inadequate
Below EAR - intake probably inadequate
