NUTRITION PRINCIPLES RICHARD CHESSOR [email protected] 07837497788.
Nutrition and food security some more principles Spring 2009
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Transcript of Nutrition and food security some more principles Spring 2009
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•Energy requirements
•Nutrient types and deficiencies
•Household food security
•Care interventions, feeding practices
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Energy needs of population depend on:
• Resting metabolic needs (BMR)
• Activity: > 1.5 BMR
• Demographic composition – ( includes pregnancy and lactation)
• Temperature
• E.g. emergencies 2100 kcals; usually around 2200 kcals; see RDAs
Energy requirements
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• Energy needs: about 2200 kcals/hd/day, averaged over popn
• Protein: about 10% of energy should be from protein.
• CHO: 3.5-4.0 kcals/g
• Protein: 4.0 kcals/g
• Fat: 9.0 kcals/g
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Nutrient types and deficiencies
Type I - reduced tissue concentration and specific clinical signs
Type II - reduced growth rate and non-specific signs
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TYPE I
growth continues in early stages specific clinical signs develop tissue concentration drops with deficiency body stores exist concentrated in particular tissues specific enzymes affected not usuallv anorexic tissue concentration independent of the other type I nutrients tissue concentration maintained in different metabolic states food sources very variable diagnosed by biochemical tests anthropometric abnormality only appears late in the deficiency .
TYPE I nutrients Iron copper manganese iodine selenium calcium fluorine thiamine riboflavine pyridoxine nicotinic acid cobalamin folate ascorbic acid vitamin A (retinol) vitamin E (tocopherol) vitamin D vitamin K
Nutrient types and deficiencies
Source: M Golden
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TYPE II nutrients potassium sodium magnesium zinc phosphorus protein
nitrogen carbon skeletons of essential amino acids threonine lysine sulphur [oxygen] [water]
[energy]
TYPE II
growth failure first response no specific clinical signs tissue concentration maintained with deficiency no body store of these nutrients not in any particular tissue general effect on metabolism anorexia common response tissue concentration dependent upon all the other type II nutrients tissue concentration may change (drop) with metabolic state ratio in foods not very variable do not give biochemical abnormalities diagnosed by anthropometric abnormality
Nutrient types and deficiencies
Source: M Golden
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TABLE 1 PERCEPTIONS AND RELATIVE PRIORITIES OF INTERVENTIONS Problem Presentation Intervention Vitamin A deficiency Striking: blindness,
increased child and maternal mortality risk
Easy in children: infrequent high dose capsules
Iodine deficiency Striking: cretinism, dwarfs, goitre
Easy: iodized salt
Iron deficiency Subtle: anemia, reduced cognitive development
Difficult: e.g. frequent supplementation
General malnutrition -- growth failure
Subtle: smaller children Difficult: community-based programs
General malnutrition -- starvation in emergencies
Striking: emaciated and dying children and adults
Easy (in principle): emergency food aid and other assistance
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Household food security.• Except in emergencies (and even then) interventions to improve food security
are pretty much the same as those to reduce poverty.
• Relevant actions:– Macroeconomic adjustment– Employment policies– Employment provision– Agricultural policies– Cash transfers (maybe conditional)– Food prices and subsidies, public distribution
• General subsidies• Targeted• Rations and quotas• Food stamps and coupons
See: ‘nutrition-relevant actions’ www.unsystem.org/scn
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Measure food security and hunger:
• FPI/CPI
• Income/exp surveys
• Food cons surveys (incl 24 hr recall)
• Food perception q’aires
• Anthropometry ?See FIVIMS meeting: http://www.fivims.net/documents/ISS/ISS_e/ISS_exesum.pdf
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ISSUES IN COMPLEMENTARY FEEDING
Weanling’s dilemma
Time for caring – feeding frequency
Quality
Timing
Bulk
Cleanliness
... and continue breastfeeding
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Complementary foods
Ideal pattern of infant feeding
6 mo
12 mo
24 mo
100%
50%
0%
Breast fed only
Breast fed and complementary foods
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Interventions in relation to the life cycle.
Antenatal care Birth attendance
Breastfeeding – initiation, exclusive to 4-6 months,
continue into second year
Child feeding practices (weaning)
Immunization
Water/sanitation/food security