Energy Balance Assessment and Body Composition I Flashcards
The science of how living organisms obtain and use nutrients to support all the processes required for existence
Nutrition
The leading causes of death are
Chronic diseases
The top 3 major lifestyle risk factors associated with heart disease, cancer, and stroke are
Tobacco, poor diet/inactivity, and alcohol
Nutrients that must be obtained form our diet because either our body cannot synthesize them at all or cannot make them in adequate amounts
Essential nutrients
Body can make it in amounts needed to satisfy its physiological requirements
Nonessential nutrients
Normally a non-essential nutrient, under certain circumstances, becomes essential
Conditionally essential nutrient
What is an example of a conditionally essential nutrient?
The essential fatty acids Linoleic and linolenic acids
Become essential in infants since the conversion of linoleic and linolenic acids to these molecules is not adequate
Arachidonic acid and DHA
What are the six classes of nutrients?
- ) Carbohydrates
- ) Lipids
- ) Proteins
- ) Vitamins
- ) Minerals
- ) Water
Vitamins and minerals are examples of
-we only need small amounts, i.e. less than a gram per day
Micronutrients
How do we measure the calories in food?
Direct calorimetry via a bomb calorimeter
In bomb calorimetry, food is placed in airtight chamber surrounded by
Water
Then oxygen is pumped into the chamber and the food is
Ignited
This causes a
Temperature increase in the water
The amount of heat required to raise the temperature of 1 gram of water 1 degree Celsius
Calorie
The amount of heat required to raise the temperature of 1 kg of water 1 degree Celsius
Kilocalorie
Not a nutrient, and it interferes with growth, maintenance, and repair of the body
-yields 7 kcal/g
Alcohol
Provide maximal amounts of nutrients for minimal number of calories
Nutrient Dense Foods
Tend to include foods that are high in fat and have a low water content with lower amount of essential nutrients
Energy dense foods
How do we calculate energy density?
ED = Kcals/mass
When a food provides primarily calories, and little else of value to our health, we say that food has
Empty Calories
Used to examine the likelihood that intake is adequate in a population
Estimated Average Requirement (EAR)
Used as a goal to help ensure adequate intake in an individual
Recommended Dietary Allowance (RDA)
Used to examine the likelihood that intake is adequate when no RDA is set for a nutrient
Adequate Intake (AI) Level
Used to examine the likelihood of excess or toxicity
Tolerable Upper Intake Level (UL)
Meet requirements of 50% of the healthy individuals in each life stage and sex
EARs
It is inappropriate to use EARs for
Individuals
Accounts for 97% of healthy individuals in specific life stage and sex
RDA
Functions to prevent nutrient deficiencies and promote optimal health
RDAs
RDAs have a built in
Safety margin
RDAs can only be established for nutrients with
EARs
Nutrient intake goals for individuals when there is not RDA because of no EAR
AI
There are no RDAs for
Infants 0-6 months of age
Formulated based on gender, growth, age, physical activity, and body size and composition
Estimated Energy Requirements
We can use direct and indirect calorimetry to estimate
Energy Expenditure (EE)
Assesses total heat loss from the body
Direct measurement of EE
Assesses respiratory gas exchange
Indirect measurement of EE
In indirect measurement of EE, 1 L of O2 equals
4.8 kcal energy
Stable isotopes such as doubly labeled water can be used to estimate
EE