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textbook dietary/exercise analyses essay option. Lecture 2a- 16 September 2013 Overview of Nutrition. Overview of lecture 1) Introduction-nutrition in a nutshell/nutritional choices 2)Nutrients defined 3)Science of nutrition 4) Next lecture- Planning a healthy diet-chapter 2.
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textbook dietary/exercise analyses essay option
Lecture 2a- 16 September 2013 Overview of Nutrition
Overview of lecture 1)Introduction-nutrition in a nutshell/nutritional choices 2)Nutrients defined 3)Science of nutrition 4) Next lecture- Planning a healthy diet-chapter 2
Choices of quantity and quality of nutrition have significant impact on the longevity and quality of a person’s life.
Nutrition-defined-narrow- Science of what we eat and its impact on us through: ingestion(I), digestion(D), absorption(A), transport(T), metabolism(M), excretion (E) (IDATME)
Nutrition-defined-broad Previous narrow definition plus psychology economics sociology and culture of food and eating
Food and hence nutritional choices depend on: • personal preference • habit • ethnic heritage or tradition • social interactions • availability, convenience and economy of food • positive and negative associations • emotional comfort • values • body image • nutrition for health
Nutrients defined: chemical substances obtained from food and used in the body to provide: a) energy, structural materials and regulating agents to support growth, maintenance, and repair of the body b) possible disease prevention and reduction
Nutrients classified Energy yielding Non-energy yielding Non-nutrients
Energy yielding nutrients -all organic-carbon containing Carbohydrates Lipids Proteins 4/9/4 kcal/gm – remember calories are really kcal 17/37/17 kjoules/gm -energy for warmth body maintenance (build new compounds/turnover)), movement
Non-energy yielding nutrients -but can assist in deriving energy Vitamins-organic Minerals-inorganic-non-carbon containing Water-inorganic
In food one has: Essential or indispensable vs. non essential nutrients vs conditionally essential Also have non-nutrients-helpful, neutral, or harmful Alcohols Phytochemicals Additives, etc How to page 9-Rolfes et al. – homework
Science of nutrition Separating fact from rumour via studies: fig 1-4 and table 1-3 Rolfes et al Epidemiological (no intervention) -case-control, cross sectional, cohort Experimental (intervention) - animal, in vitro (eg cell culture), human
Science of nutrition -must follow good scientific method: question hypothesis data interpret data conclude question (s) Figure 1-3 Rolfes et al-eg vitamin D
Animal and Human Studies all studies must take into consideration -controls -double/single blind, -subject/animal numbers, -randomisation of experimental and control groups, -placebos in some cases for controls -replication-so as to determine the validity of the variable(s) measured
SCIENCE OF NUTRITION DETERMINES : a) If people meet requirements(recommendations) (how much (minimum) needed in diet) or if one is deficient for one or more nutrients b) Nutrient recommendations-page 17 Rolfes et al DRI (EAR/RDA/AI/TUI) c) TUI-toxicity d) How to tell about adequate nutrition Watch out for hucksters