GI & Metabolism Flashcards
What are the four major functions of the GI tract?
- Motility - propulsion of food bolus from motuth to anus
- Disgestion - Breakdown of food bolus to form chyme (occurs in stomach)
- Secretion- secretion of enzymes to faciliatate digestion
- Absorption - into small bowel and colon (faciliated by digestion & secretion)
Why is Disease Affecting the GI Tract Important?
- Gastrointestinal disease is the third most common cause of death
- Gastrointestinal cancer has highest moratlity rate of cancers
- Most common cause of hospital admissions
How many GP referrals are related to GI problems?
1 in 6
What is the prevalence of contipation, dyspepsia and IBS?
Constipation - 1 in 10
Dyspepsia - 1 in 10
IBS - 1 in 20
What do the following nutritional requirements acronyms stand for? EAR LRNI RNI Safe intake
EAR - estimated average requirement (half the population needs more and half the population needs less than the EAR)
Lower Reference Nutrient Intake- does not meet the needs of 97.5% population)
Reference Nutrient Intake -suffiencient for 97.5% poplation. If RNI of ppulation is met the risk of disease is small
Safe intake- Not enough information to assess the above. However an amount that seems sufficient and not disease causing.
How much protein does an average adult require?
0.75g/kg/day
Name the 9 (10) esstential amino acids
P = Phenylalinine V = Valine T= Threonine
T= Tryptophan I= Isoleucine M= Methionine
H= Histodine
A = Arginine (During preganancy or growth the body cannot self synthesise enough)
L= Lysine
L=Leucine
Why do we needs lipids?
Energy release -TRYGLERCEROLS (1g = 9kcal)
Carbs and protein only 4kcal per g
Cholesterol & fatty acids - precursors for hormones and prostaglandins, vitamin D production
Protect vital organs
What is Lipodystrophy?
Genetic illness resulting in an inability to store fat
What is the recommended dietry intake for fat (%)?
30-35% total
11% saturated
What are the 4 dietry carbohydrate groups?
Polysaccharides – mainly starch
Disaccharides – mainly sucrose
Monosaccharides – mainly glucose and fructose
Non-starch polysaccharide (dietary fibre)
What are micronutrients?
Vitamins
Organic compounds required for normal metabolic function, which cannot be synthesised in the body – deficiency results in disease which can be treated by restoring appropriate levels of the compound
Required in small amounts (µg – mg)
Minerals
Inorganic elements which have a physiological function
Required in varying amounts from µg (‘trace elements’), mg (Fe, Mg) to g (Na, Ca)
Why is Niacin different from most vitamins?
It can be synthesised by the body using the amino acid tryptophan
Which vitamins are fat/ water soluable?
fat soluable- A,D,E & K
water soluable - B vitamins & vit C
What is the recommended dietry salt intake?
< 6g/day
What are common nutritional deficiences in the UK?
Protein/energy Iron Vitamin D Vitamin B12 Folate Vitamin C
What are the causes of nutritional deficiency?
Inadequate intake
Food availability (poverty, disability) Food choices (cost, convenience, limited range, vegans) Problems with eating (sore mouth, dysphagia, eating disorders)
Inadequate absorption
- Problems with fat absorption affects fat soluble vitamins (cystic fibrosis, coeliac disease, Crohn’s disease)
- Pernicious anaemia (B12 absorption)
Excess loss/increased requirements
Iron deficiency anaemia often arises as a result of persistent blood loss – gastric ulceration, colon cancer, excessive menstrual loss
Folic acid deficiency in pregnancy – additional requirement may not be met
What is malnutrition?
Inadequate or excess intake of protein, energy, and micronutrients such as vitamins & minerals
What are the consequences of vitamin B12 deficiency?
Can cause anaemia and/or irreversible neurological damage. Common symptoms include numbness and tingling of toes and fingertips
If untreated, more serious symptoms include limb weakness, poor coordination, altered gait, incontinence …. death
Which eating disorders are new to the DSM-V?
OSFED (other specified feeding & disorders)
ARFID (avoidant and restricitve intake feeding disorder)
Diagnostic features of Anorexia nervosa
Active mainatinance of low weight (<85% expected weight or BMI <17)
Concern about weight & shape
Types: restricting, binge/purging
Diagnostic features of Bulimia
recurrent binge eating - large amounts quickly, loss of control compensatory behaviour - vomiting, laxatives, fasting, exercise extreme shape & weight concern
binge frequency (1/wk for 3 months) not anorexia nervosa
Prevalence of Anorexia & Bulimia
95% of cases of both BN and AN are female
AN- 0.5% girls aged 15-18
BN- 1-3% girls aged 18-25
Binge eating disorder characteristics
similar to BN BUT does not inclde compensatory behaviour eg. vomiting, laxative etc
