Chapter 4 Flashcards
Classification of Nutrients (28 cards)
What is a food chain?
a simple way of describing how food starts with a producer and ends with a consumer
What does the food chain look like in food industry?
farmers and hunters - food manufacturers and processors - commodity brokers - distributors - shops - people
What are foods composed of?
hundreds of different chemical substances some of which are a natural part of the food
What are phytochemicals?
natural chemical substances found in plant foods, many of which are known to be beneficial to body health
What do phytochemicals do?
-give plants a natural colour, flavour and scent
-enable them to resist disease or attacks by predators
-enable them to grow and reproduce
-attract insects to pollinate them so they can reproduce
What are food additives?
chemical substances added to processed foods by food manufacturers which
-improve sensory qualities such as colour, flavour, texture or aroma
-preserve the food to make it last longer
-make sure the food stays stable and does not change its texture, flavour, colour etc during storage
-adds nutritional value
not all food additives are from chemicals some are natural that are extracted from plants e.g. vanilla extract from vanilla pods
what is a balanced diet?
a diet that provides a person with the right amount of nutrients for their needs
what is a diet?
the food people eat every day
what is good nutrition?
eating a wide variety of foods (mainly plant foods) that are mostly unprocessed (whole foods) and drinking plenty of water
what is malnutrition?
an insufficient, excessive or unbalanced intake of nutrients and energy that affects general health, body growth and functions and leads to a range of diet-related diseases
What does having good nutrition mean?
- Physical fitness - strength, stamina, physically active and lots of energy
- Mental health - ability to concentrate and learn, ability to stay calm and happy
- Growth and development - all body systems grow strong and work well
- Health - good resistance to disease and ability to recover well from disease or injury
What does malnutrition mean?
- Over nutrition - weight gain/obesity and a variety of diet-related diseases e.g. type 2 diabetes
- Under nutrition - weight loss, weakness and failure to grow and develop
What is a nutritional value?
The amount of specific nutrients that are found in a quantity of food (usually 100g)
What do the nutritional values depend on?
-how fresh the sample of food being tested on is (some nutrients break down the longer they are storedP)
-the variety of plant or animal food
-how the plant/animal was grown/reared
-the way the food was processed, preserved or cooked
How many kJ in 1 kcal
4.2
What is front-of-pack labelling?
To enable consumers to quickly see how much of various nutrients a food product contains
red = the food contains a high amount of the nutrients amber = medium green = low
The general advice for a health diet is to choose a mixture of labels that are mainly green but some amber and red
The % figures tell you how much of the RNI the food contains
What is nutrient density?
a measure of the number and quantity of different nutrients a food contains
e.g sugar has a low nutrient density as it is just made up of carbohydrates
whole milk are nutrient dense as it has not had any nutrients removed by processing
Some foods are fortified with extra nutrients after processing
What is biological value?
how much of a nutrient in a food is used by the body, after the nutrient has been digested and absorbed from the small intestine
What does the biological value depend on?
-the sample of food used
-how it was grown/reared
-how it was prepared for consumption
How does biological value show us how protein is used in the body?
Protein is broken down into amino acids and any excess amount that are not used are stored in that form. The nitrogen they contain is toxic so it is removed from amino acids and converted into ammonia in the liver and then into urea so it’s excreted as urine.
By measuring the amount of protein eaten and the amount of nitrogen excreted in the urine we can work out how much protein retained and used by body - BIOLOGICAL VALUE
HBV or LBV depending on how many essential amino acids they contain
What is glycemic index?
a system for rating foods according to how rapidly and how much they individually raise the blood glucose level in a person
What happens to carbohydrates when we eat them?
the carbohydrate is converted to glucose during digestion and then enters the bloodstream where it travels to the cells and provides them with energy
GI ratings
The quicker the carbohydrate food is digested and absorbed, the faster the glucose is released into the bloodstream so causing a higher glycemic response so a higher GI rating. Lower GI ratings provide a steady supply of energy which is better for long term health because it reduces the risk of a person developing type 2 diabetes
examples of low-medium GI foods
fruits, vegetables and pulses, wholegrain foods
