Why study Nutrition? • To ensure proper nutrition for yourself – For normal lifestyle – For special situations • Pregnancy • Athletic performance • Relationship with morbidity, mortality – Cancer – Cardio-Vascular Disease – Diabetes Mellitus – Stoke • Important in prevention, treatment, recovery • Prevents misinformation
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Why study Nutrition? To ensure proper nutrition for yourself –For normal lifestyle –For special situations Pregnancy Athletic performance Relationship.
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Why study Nutrition?• To ensure proper nutrition for yourself
• Environmentalists – Vegetarian/Vegans• Animal Rights activists - Vegetarian/Vegans• Concerned consumes - local produce, organic, migrant workers rights, GMOs
• Body Weight and Image• Nutraceuticals• Green Tea• Ephedra
• Nutrition and Health Benefits
Nutrition in Your Life• Food
– Derived from plant or animal sources•Provide energy and nutrients
–Used by the body for maintenance, growth, and repair
Copyright 2005 Wadsworth Group, a division of Thomson LearningCopyright 2005 Wadsworth Group, a division of Thomson Learning
What does food provide?
• Energy– Energy -- The capacity to do work. The energy in
food is chemical energy, which the body converts to mechanical, electrical or heat energy
• Nutrients– Provide Energy– Provide raw materials to build body parts
• E.g. proteins mainly provide amino acids to build muscles,skin and make enzymes, hormones etc.
• Are less important as sources of energy
– Provide materials to keep body functioning
Energy Defined
• Energy is measured in kilocalories • A kilocalorie is a unit of heat (the amount
of heat necessary to raise the temperature of 1 liter of water 1o C)
• Energy yields of common nutrients– Carbohydrates (CHO): 4 kcal/gram – Protein: 4 kcal/gram – Fat: 9 kcal/gram – Alcohol also provides energy (7 kcal/gram),
but is a toxin, not a nutrient.
Energy Density• Low Energy Density is better for nutrition• More filling so
Protein, Fat– Micronutrients Small amounts (typically milligrams daily)
Minerals, Vitamins• Nutrients (Source)
– Essential– Synthesized by the body
Non-nutrient components of food
• Fiber
• Phytochemicals
• Alcohols
Nutrients essential for humans
• Here are the known categories of essential nutrients for man. – water – calories (energy) from protein, carbohydrate or fat. – 8-10 essential amino acids (all 20 are necessary for protein
synthesis, but we can make some from other amino acids or from carbohydrate and ammonium ions).
– essential fatty acids – 13 vitamins (organic compounds required in small amounts).
These typically function as enzyme cofactors, e.g., niacin (precursor of NAD and NADP), riboflavin (precursor of FAD, FMN), pyridoxine or B6 (precursor of pyridoxal phosphate).
– 16-20 minerals (inorganic compounds required in "small" amounts).
What makes a nutrient essential?
• Omission from the diet leads to a decline in certain aspects of health.
• Restoration of the omitted nutrient to the diet before permanent damage occurs, will restore normal function to the aspects of health impaired by its absence.
• Have specific biological functions in the body. • Are needed to maintain life, but are not produced in the
body, or produced in amounts too small to maintain metabolism
• Biopterin is necessary in metabolism, but we can make all we need.
• In contrast, folic acid is equally necessary, but we cannot make it. Hence, folic acid is an essential nutrient
The Science of Nutrition –The Metric System
• Metric System – Also called System Internationale (SI)– With the primary exception of the US, the nations of the world use the SI system
• Measurements might be made in these basic units: – Length - meter – Volume - liter – Weight - gram – Temp - degrees Celsius – Energy – kilojoules
• The following set of modifying prefixes work for all basic units mentioned above: – 1kilo = 1000 (grams, or meters or liters)– 1 centi = 1/100 (grams, or meters or liters)– 1 milli = 1/1000 (grams, or meters or liters)– 1 micro = 1/1000,000 (grams, or meters or liters)