Nutrition Flashcards
Summarise healthy eating in the UK
In the UK healthy eating recommendations for the general population are set by Public Health England.
At a population level these are based on Dietary Reference Values (DRV’s). DRV’s are a series of estimates for different population subgroups for the essential macro- and micro-nutrients to prevent nutritional deficiencies. They are not recommendations or goals for individuals.
To translate the DRV’s into ‘food terms’ the Eatwell guide has been created. This is a pictorial guide to healthy eating showing the proportions in which different types of foods are needed to have a well-balanced and healthy diet. The proportions shown are representative of your food consumption over the period of a day or even a week, not necessarily each meal time.
What constitutes a healthy diet
at at least 5 portions of a variety of fruit and vegetables every day
Base meals on potatoes, bread, rice, pasta or other starchy carbohydrates; choosing wholegrain versions where possible
Have some dairy or dairy alternatives (such as soya drinks); choosing lower fat and lower sugar options
Eat some beans, pulses, fish, eggs, meat and other proteins (including 2 portions of fish every week, one of which should be oily)
Choose unsaturated oils and spreads and eat in small amounts
Drink 6-8 cups/glasses of fluid a day
What are dietary reference values
series of estimates for population for the recommended daily intake of essential macro and micronutrients
Describe the different categories for processed food
Minimally processed: rice, nuts, fresh fruit/veg; little processing to keep it fresh
Processed culinary ingredients: oil, butter, sugar and salt
Processed foods: pasta, bottled veg, canned fish, fresh bread, cheeses
Highly processed foods: crisps, biscuits, crackers, sausages, salami, ready meals
Describe low carb diets and the data associated with them
Low carb diets: <130g carbs per day (<26% total energy) may decrease triglycerides and increase HDLs while improving weight loss and reducing diabetes risk
PURE Study: prospective observational study that showed eating carbs the most increased all cause mortality but not CVD mortality (eating more fats decreased risk of death)
ARIC and PURE: indicate lowest mortality at 50-55% of energy from carbohydrates but low carb (<40%) and high carb (>70%) increased mortality- low carb more so
Describe the types of intermittent fasting diets
16/8 diet: fasting for 14-16 hours and then restrict eating to 8-10 hours
5:2 diet: eat normally 5 days a week and restrict intake to 500kcal on 2 days
Eat-stop-eat diet: 24 hour fast 1/2 times a week
Alternate day diet: fast every other day
Spontaneous meal skipping: where convenient
Describe intermittent fasting diets
Obesity - linked with lack of healthy lifestyle, not necessarily with fractionation or shorter or longer feeding intervals
Replacement of in natura or minimally processed food by ready-to-eat industrialized products = preponderant factor for weight gain and not its fractionation
Weight Loss in overweight and obese = equivalent weight and lean mass loss x continuous energy restriction
Dietary Restriction = Favour binge eating behaviour
Describe the data associated with intermittent fasting diets
There are insufficient scientific subsidies to not follow a daily food standard with meals fractioned in 5 or 6 portions throughout the day
Conducts related to this practice = based in animal studies and observational data from religious fasting (short term)
There are some randomized trials for periods of > 6 months = similar weight reduction, lipemia, CV and cancer parameters
Published studies are not sufficient to confirm the hypothesis of reversion or attenuation of: diabetes, cancer, CVD and others
Describe plant-based diets
Plant-based diets contain a host of food and nutrients known to have independent health benefits
Evidence linking red meat intake, particularly processed meat, and increased risk of CHD, cancer and type 2 diabetes provides indirect support for consumption of a plant-based diet
Describe the impact of vegetarian diets
Vegetarian diets have not shown any adverse effects on health
However, restrictive and monotonous vegetarian diets = nutrient deficiencies with deleterious effects on health
What is the advice for vegetarian diets
Appropriate advice = ensure a vegetarian diet is nutritionally adequate
Bioavailability of proteins is different- need to consume more
What is malnutrition
“Malnutrition is a state of nutrition in which a deficiency or excess (or imbalance) of energy, protein and other nutrients causes measurable adverse effects on tissue / body form (body shape, size and composition) and function and clinical outcome” (BAPEN , 2018)
The term malnutrition does include obesity, however this session will relate to “undernutrition” only.
Describe the epidemiology of malnutrition
Epidemiology: approx. £20bn/year due to under nutrition; estimated 3m people in UK are under nourished, with 1/4 admitted to hospital at risk
25-34% of patients admitted to hospital at risk
30-42% of patients admitted to care homes at risk
18-20% of patients admitted to mental health units at risk of undernutrition
70% of patients weigh less on hospital discharge
Describe the determinants of malnutrition
inadequate food interacts with disease, but increased by household food insecurity, alongside poor and unhealthy social environment
Inadequate food intake: poverty, cooking skills, isolation, bereavement, limited access
Disease related: N&V, diarrhoea, early satiety, depression, immobility, increased nutritional requirement (burns/cancer/Crohn’s)
What are the consequences of malnutrition
Consequences: reduced immunity, muscle weakness, kidney failure, depression, apathy and neglect, reduced fertility, risk of hypothermia, growth failure, stunting, deficiencies
Mortality: exponentially increases with greater body mass loss
Practical impact: increased risk of falls/#s, muscle wasting, low mood, increased admissions, reduced independence, increased infections and increased confusions
How do we diagnose malnutrition
Diagnosis: nutrition screening > nutrition assessment > diagnosis
Screening: quick and simple, during initial assessment of patient and then at regular intervals by non-nutrition professionals
Assessment: detailed and in-depth, and can involve anthropometrics - performed by dietitian or specialist nurse; first: anthropometrics - assessing weight, BMI, % weight loss; second: food record chart or food diary; thirds: bloods for albumin, CRP, creatinine and cholesterol
Describe nutritional screening
QUICK and simple, practical
During initial assessment of patient; regular intervals
By non-nutrition professional
Describe nutrition assessment
More detailed, in-depth
Could use anthropometrics
By a dietitian or specialist nutrition nurse
Why do we use nutrition screening
To assess a patient’s nutritional status and categorise into a risk
Completed by a nurse within 24 hours of hospital admission
Describe Malnutrition Universal Screening Tool (MUST)
BMI score
Weight loss score
Acute disease effect score
How do we assess malnutrition
Weight
Weight loss
BMI
Other anthropometric measures (skinfold thickness, muscle circumference, hand grip measure)
What should we do with patients
Screen all for RISK of malnutrition
Multi-system approach to assessments of malnutrition
Describe enteral feeding
Enteral feeding: This relies on delivery of a nutritious fluid past the upper GI tract and into the stomach/small intestine.
Describe paraenteral feeding
Pareneteral feeding: This involves bypassing the GI tract althtogether via delivery of nutrients into the blood.
Describe the route of delivery for enteral nutrition
A tube is placed into GI tract to deliver liquid food.
Specifically named after destination from nose: nasooesophageal, nasogastric, nasoduodenal;
Or destination through percutaneously: oesophagostomy, gastrostomy, jejunostomy
Preferred for most
Describe the route of delivery for paraenteral nutrition
A micronutrient-rich solution is adminstered slowly directky intro the blood through a venous catheter.
Necessary for some
What are the indications for enteral feeding
Indications for nasogastric feeding: inpatient with poor appetite and not meeting oral nutritional requirements/wound healing/difficulty in swallowing (e.g. Strokes)/sedated/ ventilated
Indications for gastrostomy: (tube via anterior abdominal wall - greater than 1 month feeding) for those with neurological swallowing problems, cognitive impairment or mechanical obstruction
Indications for jejunostomy: upper GI obstruction/fistulae or stomach disease; also useful for early post-op feeding and management of delayed gastric emptying
What are the indications for parenteral feeding
Indications for parenteral nutrition: gut is not working and all other routes of enteral nutrition are not usable, and only if benefits outweigh risk (prolonged obstruction/intestinal failure / ischaemic bowel / complex surgery / some oncology / severe pancreatitis)
Why may patients need enteral feeding
Upper GI problem, perhaps dysphagia or trauma, that means they cannot chew and swallow food normally.
Why may patients need paraenteral feeding
Dysfunction GI tract that is unable to digest, absorb or excrete appropriately (e.g. mid-GI blockage)
TPN administration can take more than 12 hours, so serious conseuqneces on quality of like.
Describe the complications of enteral feeding
Low risk of N&V and aspiration, tube issues/blockage, misplaced tubes (aspiration), osmotic overload of intestines, diarrhoea and constipation
Constipation due to insufficient fluid/ fibre intake
Describe the metabolic complications of enteral feeding
Due to over or under feeding- refeeding syndrome
What are the complications of paraenteral feeding
High risk of serious complications:
Blood clots
Infection
Liver failure
(clots/infection/sepsis/liver failure/electrolyte disturbances/hypos/hypers /refeeding syndrome)
Compare the training, costs and effects on GI tract of each type of feeding
Enteral- Requires basic training only to administer and maintain,
Maintains the internal structure and function of GI tract, much cheaper too
Paraenteral- Requires specialist training and support throughout feeding period, Causes atrophy of gatsrointestinal structures through underuse, Expensive, five times more costly than enteral nutrition
Describe the mechanism in refeeding syndrome
Mechanism: insulin falls and cortisol/glucagon increased to cause protein catabolism and gluconeogenesis; feeding leads to insulin secretion causing uptake of phosphorus, magnesium, potassium and glucose, so the levels all drop rapidly causing hypophosphataemia/kalaemia/ magnesaemia and sodium retention
What is meant by refeeding syndrome
“Refeedingsyndromeis a syndrome consisting of metabolic disturbances that occur as a result of reinstitution of nutrition to patients who arestarved or severely malnourished”
Refeeding syndrome usually occurs when a person has been starved for 5 days or more and then is given nutrition
Describe the consequences of a lack of phosphate
Altered myocardial function
Arrythmia
Congestive heart failure
Acute ventilatory failure
Lethargy, weakness, seizures, confusion, coma, paralysis
Describe the consequences of a lack of potassium
Arrythmia
cardiac arrest
respiratory distress
paralysis
weakness
rhabdomyolisis
Describe the consequences of a lack of magnesium a
arrhythmia
tachycardia
respiratory depression
ataxia, weakness, confusion, muscle tremors, tetany
How can we manage refeeding syndrome
daily biochemistry, vitamin supplementation and slow reintroduction of nutrition support
Describe short bowel syndrome
Short bowel syndrome: surgical removal of bowel that leaves less than 100cm of functional tract (e.g. Due to cancer/Crohn’s/ischaemia) causing dehydration, malnutrition and malabsorption
Consequences: loss of absorptive surface area, loss of efficient control by hormones and enteric nervous system, increased risk of infection
Management: focus on adequate nutrition, adequate water and electrolytes, and correction of acid-base imbalances
What is short bowel syndrome characterised by
hort bowel syndrome is characterised by significant removal of the bowel which leaves the patient with less than 100 cm of functional intestinal tract. This is usually necessary because of problems such as Crohn’s disease, cancer, ischaemia, ulcerative colitis, irradiation). Loss of bowel leads to dehydration, malnutrition, and malabsorption of micro- and macronutrients.
What is the most important surgical intervention in short bowel syndrome
Anastamosis (‘connection’) of the small intestine to the colon is the most important surgical intervention and can heavily reduce reliance on parenteral nutrition.
What is alcohol
Alcohol is an exogenous molecule that has been produced and consumed by humans for thousands of years and have played an important role in religion; supplying nutrition and energy; providing medicinal, antiseptic, and analgesic benefits; quenching thirst; facilitating relaxation; promoting conviviality and social cohesion; increasing the pleasure of eating; providing pharmacological pleasure; and generally enhancing the quality and pleasures of life. However, alcohol is a drug that has deleterious effects that can lead to negative physical, mental and societal consequences.
What is the metabolism of alcohol affected by
. The metabolism of alcohol is affected by a large number of factors including diet, gender, body-habitus, racial and genetic influences. An appreciation of these factors can lead to a greater understanding of why some individuals are more susceptible to both the acute effects of alcohol and its long-term sequelae.
Summarise alcohol metabolism
Catalase: ethanol converted to acetaldehyde in peroxisomes using hydrogen peroxide
CYP2E1: ethanol converted to acetaldehyde in microsomes using NADPH, protons and oxygen (forming water and NADP+)
ADH: reversibly catalyses the production of acetaldehyde in the cytosol, reducing NAD+
What happens to the acetaldehyde
Acetaldehyde metabolism: converted to acetate in mitochondria, reducing NAD+ and using ALDH2
What are the consequences of alcohol metabolism
Consequences of metabolism: increased NADH:NAD+ ratio, increased ROS formation and acetaldehyde formation
Describe the physiological effects of alcohol
CNS – Wernickes encephalopathy, Cerebral atrophy, Cerebellar syndrome, Optic Atrophy, Peripheral neuropathy
CVS – Hypertension, Alcoholic cardiomyopathy, Stroke
GIT – Oesophagitis, Gastritis, Oesophageal and Gastric cancer, Pancreatitis, Pancreatic cancer, Alcoholic Hepatitis, Cirrhosis, Liver Cancer
GUT – Glomerulonephritis, Renal failure
LMS – Gout, Fractures, Myopathies,
Endocrine & Reproduction – Pseudocushings, Impotence, Subfertility, Breast Cancer, Fetal Alcohol Syndrome
Describe the physiological effects of alcohol
Alcohol is a drug of addiction and is frequently used in conjunction with other recreational drugs of abuse. Alcohol is frequently a factor in a number of psychological conditions. While it is often seen by sufferers of mental illness as a way of dealing with the problem; the effect is frequently the opposite.
Describe the general signs and symptoms of G.I disease
Malaise: generally unwell w/non-specific cause
Rapid weight loss: usually unintentional and uncontrollable
Anorexia
Anaemia: reduced ability to carry oxygen w/fewer or smaller erythrocytes
Explain some terms associated with G.I disease
Melaena: black tarry stool, upper GI blood altered by gut flora, enzymes and secretions
Steatorrhoea: sloppy, oil faeces caused by excess fats in stool; ?digestive failure ?reduced bile/lipase activity
Dysphagia: difficulty swallowing; Odynophagia: pain when swallowing
Ascites: fluid accumulation in abdominal cavity (cancer/malnutrition/liver failure)
Haematemesis: vomiting blood
Describe symptoms associated with the whole body
Cachexia: muscle wasting 2/2 undernutrition
Obesity: nutritional imbalance
Lymphadenopathy: enlarged lymphoid tissue e.g. In neck
Jaundice: yellowing of skin, sclera and mucous membranes due to increased circulating bilirubin
Describe symptoms associated with hands
Koilonychia: spooning of nails (iron deficient anaemia)
Leuconychia: partial/complete whitening of nails (nutrient deficiency)
Clubbing: enlarged concave appearance (Crohn’s/cirrhosis/malabsorption)
Dupytren’s contracture: pulls fingers to bent position (diabetes/alcoholism)
Tachycardia (via radial pulse)
Tremor
Describe symptoms associated with the abdomen
Palpable organ enlargement
Abdominal tenderness (local obstruction/infection)
Distension
Describe symptoms associated with the anus and rectum
Haemorrhoids: swollen superficial blood vessels that itch and bleed
Fistula: alternative pathways to outside
Fissure: tear in mucosal lining of peri-anal tissue
Proctitis: inflammation of inside of rectum
Alcohol and other causes of G.I symtpms
Alistars and benjis notes
