Medi Flashcards
What is food?
“substance consumed by people and animals that provides nutrients to sustain life”
factors influencing food choice:
-preference
-social interaction
-pos/neg associations
-availability
-tradition/culture
-habit
What is nutrition:
“Nutrition is the intake of food, considered in relation to the body’s dietary needs”
organic compounds:
- protein, carbohydrate, lipids and vitamins
inorganic compounds:
-minerals
-water
key nutrients:
– water
– carbohydrates – lipids
– proteins
– vitamins
– minerals
energy- yielding nutrients
…atwater factors
carbohydrates: 17 kj/g
protein: 17 kj/g
fat: 37 kj/g
alcohol: 29 kj/g
micronutrients:
.Vitamins:
-allow the body to obtain energy from carbohydrate, fat and protein.
-organic
Minerals:
-inorganic
-found in bones, teeth and body fluids.
water:
req for:
* digestion
* Absorption
* Dissolving nutrients
* Eliminating waste
* Thermoregulation
=50-80% of body weight
energy balance
*body weight is stable when energy consumed is = to energy expended.
* When energy consumed is greater than energy expended, weight increases.
* When energy consumed is less than energy expended, weight decreases.
energy in:
When food is burned, energy is released as heat
Gives direct measure of food’s energy value
Bomb calorimeter
* Measures available energy from foods (Gross Energy)
* Human body cannot metabolise all available energy
* Metabolisable energy: available energy
energy in: other factors
Appetite prompts a person to eat – or to not eat.
* Hunger motivates us to eat and is controlled by the
hypothalamus.
* Satiation causes us to stop eating; receptors in the stomach stretch, and hormones such as cholecystokinin increase.
* Satiety should remind us not to eat again until the body needs food.
energy out: basal metabolic rate
BMR:
-Sum total of minimal activity of all tissue cells of body under steady- state conditions such as:
* Maintaining body temperature
* Lungfunction
* Heartbeating
-Differs based on weight (particularly lean body tissue), age, life stage, gender
energy out: voluntary muscular activity/ thermic effect of exercise
Thermic effect of exercise (TEE) ~15-30% of daily EE – Musclesneedenergytomove
– Heartandlungsmustdeliveroxygen/nutrients
– Variesbasedonintensityanddurationofexercise
energy out: thermic effect of food
-Ingestion of food causes an increase in EE over several hours
-Thermic effect of food (TEF) ~ 7 – 10% 24hEE
.Changes in EE in response to food
.Energy is used for: nutrient absorption, transport, storage and metabolism
