Essentials of nutrition Flashcards
What is nutrition?
The sum of all processes involved in how organisms use nutrients to support body function
What are the 6 nutrients that must be obtained from the diet?
Protein Carbohydrates Fats Vitamins Minerals Water
What are the 5 main functions of carbohydrates?
How many Kcal/g ?
- Energy storage
- Energy production
- Building macromolecules
- Lipid metabolism
- Sparing protein
4Kcal/g
What are the main functions of protein?
How many Kcal/g?
- Enzymes + hormones
- Wound healing + inflammation ( clotting factors + acute phase proteins)
- Protection : Keratinised skin layer
- Transport
- Acid base balance
- Energy production ( amino acids used in gluconeogenesis)
4Kcal/g
What are the main functions of fat?
How many kcal/g?
Insulation + protection
Energy storage
Regulating signalling ( e.g menstrual cycle)
Aiding digestion: Some substances are only lipid soluble
9Kcal/g
What are the main functions of water?
Shock absorber + lubricant
Transport
Medium for chemical rxns
Temperature regulator
What is a calorie?
The amount of energy in the form of heat needed to heat one gram of water by one degree celcius
What are vitamins and what 2 classes may they be?
Complex organic structures
Can be water soluble or fat ( lipid) soluble
What are minerals? ( ions)
Inorganic substances not directly used for making energy
Examples: calcium, phosphorus, potassium, sodium, chloride
What factors affect nutritional requirements?
Age Weight Activity level Disease/pathology Physical and psychological health Metabolic state ( catabolic, normal, anabolic) Absorptive capacity Goals + duration of nutritional support : Undernourishment/over nourishment
How is TEE calculated?
How is REE calculated in the acutely unwell?
BMR/REE + DIT + energy expended in activity
In the acutely unwell REE = BMR + Stress
What is REE?
The energy expended lying still at complete mental and physical rest after an overnight hour fast with no prior stimulants in the last 24 hours
What is BMR?
The rate at which the body uses energy to maintain basic functions AT REST
Based on PENG guidance what is the range of Kcal/kg ?
20 - 35 Kcal / kg of body weight or free fat mass
What about for those at risk of refeeding syndrome?
10 Kcal/kg body weight/FFM to reach full needs by 4-7 days
In extreme cases only 5Kcal/Kg
What are PAL factors?
Combine DIT + energy expended in activity ( physical activity)
How do we calculate TEE?
How do we calculate REE ?
BMR/REE + DIT + Energy expended in activity
TEE = REE X PAL REE = Body weight/FFA X Kcal/kg ( 20-35)
What are typical protein requirements?
1.0-1.5g/Kg/day
Up to 1.9g/Kg/day for anabolism after injury
Lower protein diet in those with CKD of 0.8-1.0 g/Kg/day
What are typical fluid requirements?
Pyrexic patients require an additional 2.0-2.5ml/kg for each degree > 37
18-60 = 35ml/Kg/day
>60 = 30ml/Kg/day
20-25 ml/kg/day in the elderly and those with renal or cardiac disease
What does PENG guidance generally suggest?
20-25Kcal/Kg
- 25-30 for ICU patients
- 75g/Kg
- 1-1.5 for malnourished
What is re feeding?
What is re feeding syndrome?
What are some consequences of re feeding syndrome?
How do we treat re feeding syndrome?
Process of re introducing food after malnourishment or starvation
Potentially fatal shifts in fluid and electrolytes that occur when re feeding occurs
Arrhythmias, death
Slow calorie increase 10-20 Kcal/kg/day
Monitoring electrolytes
Vitamin supplements
Who is at risk of re feeding syndrome?
Any patient who has had little or no food intake for 5 days
What are the main feeding routes?
Food - as long as functioning gut
Oral nutritional supplement
Enteral feeding tube
Parenteral nutrition: Peripheral or central vein. Used when the GI tract is non viable or if oral/enteral intake is insufficient to sustain life. Also when complete bowel rest is needed after surgery
