Food, nutrition, health Flashcards
Why do we need to eat?
Grow Repair Replace Reproduce Optimal function including: brain, muscle, immunity
What are the three macronutrients?
Carbohydrates
Protein
Fats
Sugars in the body
Glucose is essential for brain metabolism
Glucose in blood obtained in fed state from carbs in diet
Cannot be made from fat (apart from glycerol)
Sugars important signals on cell membranes
When in fasted state, where are sugars released from?
Glycogen stores
Body protein
What is dietary fibre?
Non starch polysaccharides and lignin
T/F dietary fibre is indigestible in small intestine
True
May be fermented by bacteria in large intestine
Soluble fibre like pectin reduce rate of digestion
Insoluble fibres like wheat bran increase stool output
What are fructo-oligosaccharides?
Pre-biotics
Not digested by brush border enzymes
Fermented in colon
May promote colonic health and growth of friendly bacteria
What is the role of dietary fats?
Energy - fat stores
Essential fatty acids
Help carry fat-soluble vitamins
Role of lipids in the body
Store of energy
Structural role in cell membranes
Metabolic functions
What are the structural factors affecting properties of fatty acids?
Number of C atoms (chain length)
Presence of double bonds - saturated and unsaturated fatty acids
- cis and trans isomers
- position of double bond, essential fatty acids
What are essential nutrients?
Needed in the body
Not synthesised in body
Must be in diet or get a deficiency disease
What are the roles of essential fatty acids?
Cell membranes
Biologically active compounds eg eicosanoids
Growth and development
Why do we need a range of proteins in our diet?
To get all essential amino acids
What are vitamins?
Essential organic substances that occur in food in small amounts and are necessary for the normal functions of the body
Cannot be synthesised by human cells
Usually act as co-enzymes
As enzymes are in limited amounts excess vitamin intake is unnecessary and may be toxic
What are examples of water soluble vitamins?
B complex vitamins and vitamin c
