10 Human Nutrition Flashcards
What is IAXM?
Ingestion and digestion
Absorption
Excretion
Metabolism
Factors that determine nutritional status
Biological factors
Pyschological factors
Social factors
Energy expenditure
Presence of disease
What are the biological factors?
Genetic background
Digestion, absorption and excretion
Age and phase of lifecycle
Which individual responses to nutrients are determined by genes?
Digestion
Absorption
Metabolism
Excretion
Taste
Satiety
What are the demands of nutrients in different physiologic state across the lifecycle?
dependent on mother -> sex hormones -> muscle mass increases, physical activity stabilizes -> muscle mass declines, fat mass increases, bone mass declines
What are the psychological factors?
Satiety
Appetite
Palatability of food
What are the social factors?
Availability of food
Cultural customs
Why is nutrition important?
Prevention, progression and management of diseases
- chronic diseases
- surgical and anaesthetic conditions
Main classes of nutrients
Energy sources (carbohydrates, fats, protein)
Essential fatty acids
Essential amino acids
Vitamins
Minerals
Role of fiber
Indigestible carbohydrate -> regulate gut motility and transit (X energy source)
10 essential amino acids
PVT TIM HALL
Phenylalanine
Valine
Tryptophan
Threonine
Isoleucine
Methionine
Histidine
Arginine
Leucine
Lysine
Types of essential fatty acids
Linoleic acid
alpha-linoleic acid
Major purposes of nutrients
- To supply the energy needed for the body to perform work
- To provide the building blocks for synthesis of other important molecules
- To support the function of metabolic pathways
What is BMR?
Basal metabolic rate - energy required to maintain normal physiological functions when the body is at rest
What is the BMR affected by?
Gender (male > female)
Age (child > adult)
Health (effects elevated by fever, hyperthyroidism, pregnancy, lactation) (effects lowered by hypothyroidism)
Hormones (effects elevated by high levels of thyroid hormones, growth hormones, sex hormones, epinephrine and cortisol)
What is the total daily energy expenditure (TEE) a sum of?
BMR
energy used up during physical activity
thermic effect of food
3 depots of fat in body
Visceral fat (within abdominal cavity)
Ectopic fat (e.g. cardiac and pharyngeal fat pads)
Subcutaneous fat (under the skin)
Energy content from carbohydrates, proteins and fat in kcal/g
Carbohydrates - ~4 kcal/g
Proteins - ~4 kcal/g
Fat - ~9 kcal/g
What is DRI?
Dietary Reference Intakes
What are the four dietary reference standards in DRI?
Estimated average requirement (EAR) - meet the requirements of 50% of healthy individuals
Recommended dietary allowance (RDA) - meet the requirements of 97-98% of healthy individuals
Adequate intake (AI) - estimate of nutrient intake by healthy people that are assumed to be adequate
Tolerable upper intake level (UL) - highest level likely to pose no risk of adverse health effects to almost all individuals
What is MUST?
Malnutrition Universal Screening Tool
5 Steps of MUST
BMI score (>20 = 0, 18.5-20 = 1, <18.5 = 2)
Weight loss score (unplanned weight loss in past 3-6 months <5% = 0, 5-10% = 1, >10% = 2)
Acute disease effect score (If patient is acutely ill AND there has been no nutritional intake for >5 days = 2)
Overall risk of malnutrition (add scores together, 0 = low risk, 1 = medium risk, 2 or more = high risk)
Management guidelines
Forms of nutritional assessments
Anthropometric measurements
Biochemical data
Dietary data
Examples of anthropometric measurements
BMI
Waist-to-hip ratio
Mid-arm circumference
Skinfold thickness
