What is Nutrition
The science of foods and nutrients and other substances they
contain
Their actions within the body, including ingestion, digestion,
absorption, transport, excretion
Social, economical, cultural, and physiological implications of
food and eating
What is Food
Products derives from plants or animals that can be taken
into the body to produce energy and nutrients for the
maintenance of life and growth and repair of tissues
Certain food choices depend on:
o Preferences
o Habit
o Ethnic heritage
o Social interactions
o Emotions
o Availability/convenience
o Nutrition, health benefits
Diet
The food and beverages a person eats and drinks
Nutrients
Chemical substances obtained from food and used in the body
to provide energy
Support growth, regulating agents
Maintenance and repair of body tissues
o Body contains, carbohydrates, protein, and minerals
Classes of nutrients
o Carbohydrates
o Lipids (fats)
o Proteins
o Vitamins
o Minerals
o Water
Macronutrients
o Required in large amounts per day (grams)
Micronutrients
o Required in small amounts (milligrams)
Essential Nutrients
o Nutrients a person must obtain from food because the
body cannot make enough on its own
Inorganic Nutrients o Nutrients that contain no carbon
o Eg water and miners
Organic Nutrients
o Nutrients that contain carbon or bonds with carbon
Carbohydrates, fats, proteins, vitamins
Energy yielding nutrients
o Nutrients that can be broken down to provide energy to
te body
Carbohydrates, lipids, protein
Phytochemicals
o Non nutrient compounds found in plant derived foods
that have biological activity in the body
Functional foods
o Foods that contain physiologically active compounds
that provide health benefits beyond nutrients
Eg yogurt
Nutraceutical
o Product isolated or purified from foods
o Physiological benefit
o Provide protection against disease
Eg fish oil pills
Inorganic Organic Macronutr. Micronutr.
Minerals Carbohydrates Carbohydrates Vitamins
Water Protein Protein Minerals
Lipids Lipids
Vitamins Water Non-Energy Energy Yield
Minerals Carbohydrates
Water Protein
Vitamins Lipids
Energy yielding Nutrients
Energy available from foods:
Carbohydrate 4 kcal/g
Protein 4 kcal/g
Fat 9 kcal/g
Alcohol 7 kcal/g
•For example: 1 slice of bread with peanut butter
• 16 g carb x 4 kcal/gram = 64 kcal
• 7 g protein x 4 kcal/gram = 28 kcal
• 9 g of fat x 9 kcal/gram = 81 kcal
173 kcal
Energy Density
Measure of the energy food proves relative to the weight of
the food
o Food with high energy density provides more energy
per gram
Calories
o Unit by which energy is measured
o 1000 calories = 1 kilacalorie Breaking bonds release energy
Some of the energy is released as eat
Some of the energy is used to send electrical impulses to the
brain to move muscles
Energy can be stored
o If energy nutrients are not used as fuel they can be
stored as fat
o Carbs can be stores as glycogen
o Energy in = Energy out = weight stays the same
o Energy in is more than energy out = weight gain
o Energy out is more than energy in = weight loss
Protein
o Provides energy
o Structural building blocks
o Fuel source, also needs carbohydrates and fat
Nutrition Research
Cohort
o Following groups of subjects over time
Cross Sectional
o Population is chosen and samples are taken at one
period in time
Case Control
o Collects samples with a condition (case) and a sample
without condition (case)
Experimental Studies
o Laboratory based animal studies
o Laboratory based in vitro studies
Studying the effects of a variable on a cell, tissue,
or molecule from another living organism
o Clinical trials
Subjects adopt new behaviour to see if it
promotes or prevents disease
Eg subjects start exercising
o Double blind randomized clinical control trials
Neither participant or researcher are aware of
who is getting treatment
Analyzing Research
o Journals
o Correlations vs. causes
o Positive and negative correlation
Dietary Reference Intake (DRI)
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