Macronutrients/Protein energy, Malnutrition Flashcards
Is dietary lipid essential
Some are essential
Major constituent of membrane phospholipids
Precursors of eicosanoids
Linoleic acid
C18:2 w6 (from methyl end)
Linolenic acid
C18:3 w3 (from methyl end)
Requirement of dietary lipid
2-5g/day, UK recommendation
UK diet 8-15g/day, deficiency v rare
Increased intake of w3 may provide protection against CVD and for developing brain
CVD risk factors
Genetic susceptibility Smoking Sedentary lifestyle HTN High serum cholesterol (LDL) Obesity Diabetes Transfat intake
Diet and CVD
Increase in sat FA leads to increased LDL and total cholesterol
Blood cholesterol can be lowered by increasing polyunsaturated FA in diet
Increase in trans fat, increased LDL and decreased HDL
Types of fat
Cis
Trans
Unsaturated
Trans and unsaturated fats look similar, have similar effects
Dietary fats and cancer
Immigrants suffer types of cancer found in the host population rather than type more common in their country of origin (breast, colon, pancreas, prostate)
High fat intake or obesity? Cause unclear
Carbohydrates, types
Starch, non starch polysaccharides (fibre), sugar (mainly sucrose)
Mainly plant origin except lactose and v small amount of glycogen
Not needed in theory but has protein sparing effect
Low CHO diets lead to fat utilization and ketosis
Monosaccharides and sources
Glucose, small amounts in fruit
Fructose, small amounts in fruit
Sorbitol, commercially prepared mainly in diabetic foods
Inositol, in fibres as hexaphospahte (physic acid), interferes with Fe, Ca absorption
Disaccharides
Sucrose, UK consumption 10.5g/day
frequency of consumption more important than total amount
Lactose, no adverse health effects
Many non Europeans can tolerate it
Polysaccharides
Starch, v common, crystalline and insoluble
Fibre, insoluble
Cereal, vegetables, fruits
NSP rich foods low in energy, high in bulk
Decreased intake, related to constipation, diverticular disease, appendicitis, colon cancer
Why do we need protein
Essential AA needed for synthesising new protein catecholamines thyroid hormones NT haem gluthione
Protein quality, plants vs animal
Proteins of animal origin more effective in supporting growth of animals than in plants
High quality proteins, higher utilization, less waste as AA pattern nearer that of body protein
Low quality proteins deficient in some AA
Mixture of low quality proteins complement deficit (imp in countries with a mainly vegetarian diet)
Protein requirements per kg of body mass/day
As you grow older, the protein requirement g/kg/day decreases
Protein recommendations
Infants
Pregnancy
Lactation
Infants, based on milk intake of breast fed infants showing satisfactory growth
Pregnancy, compatible with protein deposition for 3.3kg infant
Lactation, based on protein content of human milk
UK status regarding deficiencies
No group in the UK likely to be deficient
Importance of protein often overestimated
Excessive intake may lead to bone demineralization/deterioration of renal function in renal disease
Protein energy malnutrition, consequences
Growth failure
Marasmus
Kwashiorkor
Marasmic kwashiokor
Consequences of childhood malnutrition
Stunting of growth, normal weight for height
Growth failure, low heigh for age
Classification of PEM by BMI
Acceptable/desirable, 18.5-25
Moderate PEM 17-18.4
Moderately severe PEM 16-17
Severe PEM <16
Extreme forms of PEM
Marasmus
Kwashiorkor
Marasmic kwashiorkor
General lack of food as opposed to specific deficiency of vitamins or minerals
Causes of childhood PEM
Poverty
Poor sanitation
Infection
Marasmus, prevalence in developed and developing countries
Any age of vulnerable groups in a population in both developed and developing countries
Developing countries
chronic food shortage/acute famine (normally in 1st year of life)
Developed countries
socially, economically disadvantaged groups
discord’s of appetite and nutrient absorption, cancer, AIDS
Marasmus symptoms
Extreme emaciation Loss of body fat reserves Muscle wasting Protein loss from vital organs Impaired immune response Loss of intestinal mucosa=>impaired absorption Diarrhea and apathy
Kwashiorkor symptoms
Additional to marasmus symptoms
Severe pitting, painless edema
Liver enlarged, fat infiltration
Changes in color, texture of hair dermatitis
If v severe, can lead to permanent mental retardation
Kwashiorkor causes
Infection often precipitates kwashiorkor
Not specifically a protein deficiency with adequate energy
Most likely a general food deficiency with added deficiency pf antioxidant nutrients not being able to cope with added oxidative infection stress
Infection increases protein req
Marasmic kwashiorkor
Not clear what determines which form
Both can be found in 1 family
Child can switch from 1 to another
Treatment of PEM
Fluid and electrolyte balance first ORS, 8tsp sugar, 1tsp salt in 1l boiled water Dextrose solution Dilute milk Normal food when tolerated
